Engine buildup!!! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Bandit · 05-21-2002, 02:01 PM

I have purchased a set of heddman headers, an Edelbrock Performer intake, and a Edelbrock performer 600cfm manual choke carb.

The truck is a 69 GMC 910 with a 350 in it. Currently, it has the stock intake, 490cfm Quadrajet, RV cam, 305 heads ( I know they suck! ) 10:1 pistons .030 over, and yes, a Powerglide tranny!

With installing my new purchased equipment, do you guy's think there will be a noticable increase in power? the truck has dual exhaust of course, but it is like, 2 inch pipe, is this REALLY bad or will it be okay?

Must the engine be lifted to install heddman headers or will they fit in with the engine on the mounts?

Any help is much appreciated, If you have any tips on the intake and carb, please share!

I need all the help I can get!!!

Bandit

Low69CST · 05-21-2002, 02:13 PM

you can install the headers with the motor in. The 2 inch pipe should be OK, not ideal though.

------------------
'69 CST Short fleetside
Lowered, 400 small block, 700R4, 4 wheel disc brakes, front & rear sway bars
See my truck at: http://www.geocities.com/low69cst/
Student at the University of Kentucky.
Feel free to message me on AOL, SN- SS95ZQ8
My Dad's projects:
72 Short Fleet 4x4 Chyenne Super
72 Long Fleet 4x4 Chyenne Super
Both 350 autos restored original

Patrick Sullivan · 05-21-2002, 02:45 PM

I think you'll like the new carb and intake. When I slapped a new Edelbrock carb on mine, I didn't notice too much power improvement, but it sure ran a lot smoother and more reliably. You'll probably notice more improvements with the intake.

If you haven't already, a worthwhile upgrade is an HEI distributor. It's like night and day compared to the old points stuff.

Bandit · 05-21-2002, 02:57 PM

Thanks for the replies guys! What would be your guess as far as horsepower gain from the header, intake, and carb installation. The Performer intake as I believe is better for torque than it is horsepower, which is good with the powerglide. Would a 40hp gain be too generous?

Thanks again!

Bandit

Bandit · 05-21-2002, 03:28 PM

I went ahead and got the casting number off the block, it is 3970010 which is either a 68 327 or a 69-78 or something 350. The guy I bought the truck off said the engine was a four bolt main from a 73 z-28 and with checking the other numbers, I came to the conclusion he wasn't bullsh!ting me. The engine stock was 245 hp, mind you, the heads had been changed as earlier stated to 305's. How much power loss would there be from these heads being installed. My comression ratio is about 10.5:1 i figure because I have to run premium all the time. Does high compression mean higher hp, or just a cleaner burn?

*67Fleetsidedream* · 05-21-2002, 03:45 PM

Just a note. Having 305 heads on a 350 will cause detonation or "pinging". Get yourself some 350 heads pretty soon or start running 110 octane. Detonation will kill a engine in a heartbeat. Been there, done that and got a T-shirt.
Ben

------------------
67 Fleetside Custom C-10
SBC 350 .030 9:1 comp.
Comp Cams Extreme Energy XE256H-10
Carter AFB 600
Edlebrock performer intake
Screw in rocker studs
Oversize valves
Scat 350 crank
Everything balanced within one gram.
Marine grade plywood bed(looks awsome)

68 with 350 TPI · 05-21-2002, 04:36 PM

I would get a adj fuel pressure regulator to go with the carb.

Those edelbrock carbs tend to load up if they have more than 4-6 PSI of fuel pressure.

what will happen is it will push the needle out of the seat and load up pretty bad.

Some of those carbs are worse than others but I havent seen many that run good at 6psi and over.
PS. that goes for 600-750 edelbrock carbs as well as the old carter AFB's.

Bandit · 05-21-2002, 05:32 PM

Why do the 305 heads cause detonation, or pinging? Don't they just boost compression due to the smaller combustion chamber?

Anyways, I just pulled the oil pan off the engine and to my suprise I found not one, but two ends of dipsticks. They have been brocken off right around the full mark. Has ANYBODY ever seen this before????? Also there were three self locking nuts off that plate that is attached beneath the crank. Most of these nuts were loose and I'm sure glad I pulled the pan off!!

P.S. What is the best octane boost? I usually use Super 104+ and it seems alright, but all suggestions are appreciated!

Bandit

Bandit · 05-21-2002, 06:22 PM

Hey all, I'm putting in a new front and rear seal and I need some assistance on installing them. What kind of silicone should I use etc.?

Bandit · 05-21-2002, 07:00 PM

back to the top

busterwivell · 05-21-2002, 11:18 PM

Whoa! I don't get it! 305 heads on a 350? 10.5 compression? junk in the pan? I think (IMHO) you should rethink the whole thing. and a powerglide? a 2 speed? I don't think this thing will do what you want it to do, no matter how much money you throw at it. What is your goal? daily driver? drag strip special? street bruiser? Tell us what your ultimate plan is, but I think (again, IMHO) you're headed in a couple of different ways, and setting yourself up for disappointment.
Bill - Tucson

------------------
56 Studebaker 2 dr Wagon
66 Chevelle 2 dr 4 speed
71 C30 Longhorn
86 Monte Carlo SS
96 Tahoe

Bandit · 05-21-2002, 11:52 PM

It's the kind of thing that I put 12k miles on in the summer, park it for the winter. I would like it to have better torque for off the line, but I don't plan on having it see over 5000 rpm. Headers are more or less for sound and gas mileage.

bigjimzlll · 05-22-2002, 12:34 AM

305 heads have small combustion chambers..along with limited flow, also smaller valves..they are a lighter casting, which makes them crack prone, also they wont desipate heat as well...which may cause hot spots which lead to detonation...if you have 10-1 pistons..which are for a 64cc head, the C/R will be a little over 10.5-1...with the small cam thats a lot of compression. Now a 64cc head and a bigger cam, like in the 268-270 range the motor will perform better, but with the 2 speed tranny, your kinda between a rock and a hard place. maybe a stall converter and 4:10s and ...i dont know...a TH350......

dmnall · 05-22-2002, 12:53 AM

One Thing I would do if I were in your case would pick up a either set of Vortec Iron Heads or even the Etec Heads from Edelbrock. Either heads will out flow your current heads and give you a little more power and then I would definitely rebuild the engine and put either a TH350 or a 4L60 Tranny and get rid of that damned powerglide !! For street use the Powerglide is crap but either a 4L60 (700R4) or TH350 will be better for the street and give you a little better gas mileage !!

Here is my Engine Setup and my gas mileage just sucks but hell this is what I get for building a 350 like this

91 350 (non roller block but can accept the OEM Roller Cam and Lifters), L79 66 Corvette Cam, 3890462 Corvette Fuelie Heads, Flat Top Piston, Carter 9635 625 CFM Electric Choke, Edelbrock Performer, accell HEI, MR Gasket Headers(Old headers but were free) and I am running around 10.5 - 11.5 somewhere around there. And I am running approximately 350 HP and I have to run nothing less then 91 Octane (had to back my timing off just to run 91 effeciantly) and I am running TH400 Tranny w/ 3.73:1 Gear Ratio. My Gas mileage blows but I will not change my heads unless I have to but if I were running 305 Heads, I would get me a set of Vortecs in a heartbeat!!

------------------
Truck #1 68 Chev LWB Fleet w/ Wood Floor (Sucks Gas and Hauls Ass!) and in process of Body Work...

Truck #2 1994 GMC Sierra SL w/ 4.3L Vortec V6, 4L60E Auto!!

Bandit · 05-22-2002, 01:36 AM

Hey DMNall, What are your RPM's at 65 mph??

Tim Rich · 05-22-2002, 10:17 AM

The pinging comes from the higher compression, which is what higher octane prevents. That's why higher compression engines require premium gas, and why premium gas is a waste of money unless you need it.

Glad my truck doesn't need premium - $1.11 a gallon's bad enough.

------------------
Tim Rich
Kennesaw, GA
72 Stepside
65 Must@ng

busterwivell · 05-22-2002, 11:20 AM

$1.35 here. The Studebaker has 10:1 flattops, roller rockers, dart heads, and needs 91 octane. Paid 189.9 per gallon outside DelMar last month. Glad the 700R and 3:55's let me get 23 MPG.

------------------
56 Studebaker 2 dr Wagon
66 Chevelle 2 dr 4 speed
71 C30 Longhorn
86 Monte Carlo SS
96 Tahoe

Bandit · 05-22-2002, 12:42 PM

The thing is, My gas mileage is great with 22-23 mpg. I rev 3100 in the 65-68 range with the two speed and what I believe are 3.23 gears. I've been told that my rpm's sound too high for them to be 3.23's. People always say it sounds more like 3.73's.

Anyway, what kind of gas mileage increase can I expect from adding the headers intake and carb. I'd like to see 25, is this outrageous??

Bandit

05-21-2002, 02:45 PM	#3
Patrick Sullivan Transcendental Trucker Join Date: Dec 2001 Location: Rockaway Beach, OR Posts: 374	I think you'll like the new carb and intake. When I slapped a new Edelbrock carb on mine, I didn't notice too much power improvement, but it sure ran a lot smoother and more reliably. You'll probably notice more improvements with the intake. If you haven't already, a worthwhile upgrade is an HEI distributor. It's like night and day compared to the old points stuff. __________________ Patrick Sullivan \| sullivan@oregoncoast.com Rockaway Beach, Oregon 1972 Chevy Cheyenne C-20 1998 Dodge Dakota 4x4 So, fill to me the parting glass And drink a health whate'er befalls... Then gently rise and softly call Goodnight and joy be to you all!

05-21-2002, 04:36 PM	#7
68 with 350 TPI Registered User Join Date: May 2002 Location: Wingate NC Posts: 456	I would get a adj fuel pressure regulator to go with the carb. Those edelbrock carbs tend to load up if they have more than 4-6 PSI of fuel pressure. what will happen is it will push the needle out of the seat and load up pretty bad. Some of those carbs are worse than others but I havent seen many that run good at 6psi and over. PS. that goes for 600-750 edelbrock carbs as well as the old carter AFB's. __________________ Life is good with a 6-71 supercharged 355 in a 72 camaro

05-21-2002, 11:18 PM	#11
busterwivell Registered User Join Date: Jan 2002 Location: Sahuarita, AZ USA Posts: 2,033	Whoa! I don't get it! 305 heads on a 350? 10.5 compression? junk in the pan? I think (IMHO) you should rethink the whole thing. and a powerglide? a 2 speed? I don't think this thing will do what you want it to do, no matter how much money you throw at it. What is your goal? daily driver? drag strip special? street bruiser? Tell us what your ultimate plan is, but I think (again, IMHO) you're headed in a couple of different ways, and setting yourself up for disappointment. Bill - Tucson ------------------ 56 Studebaker 2 dr Wagon 66 Chevelle 2 dr 4 speed 71 C30 Longhorn 86 Monte Carlo SS 96 Tahoe __________________ Bill - Tucson, AZ 47 Chevrolet 2 dr sedan 56 Chevrolet 210 2 dr sedan 66 Chevrolet Malibu 2 dr 4 speed 71 Chevrolet C30 Longhorn 86 Chevrolet Monte Carlo SS (Sold) 01 Chevrolet Tahoe IM - BUSTERWIVE@aol.com

05-22-2002, 12:34 AM	#13
bigjimzlll Senior Member Join Date: Dec 2001 Location: Redding,CA...USA Posts: 4,736	305 heads have small combustion chambers..along with limited flow, also smaller valves..they are a lighter casting, which makes them crack prone, also they wont desipate heat as well...which may cause hot spots which lead to detonation...if you have 10-1 pistons..which are for a 64cc head, the C/R will be a little over 10.5-1...with the small cam thats a lot of compression. Now a 64cc head and a bigger cam, like in the 268-270 range the motor will perform better, but with the 2 speed tranny, your kinda between a rock and a hard place. maybe a stall converter and 4:10s and ...i dont know...a TH350...... __________________ It's called "drag racing" if they called it "tic..tic..WHAM!..BANG! F*&K!!!", they'd have to keep the magazines under the counter with the other men's publications click the clicky to join the site.... http://67-72chevytrucks.com/vboard/payments.php 67 lwb..first hotrod in 25 years..540 best ET is 9.45 @ 141.44 Anderson,CA

05-22-2002, 12:53 AM	#14
dmnall Registered User Join Date: Apr 2001 Location: Goleta, CA Posts: 505	One Thing I would do if I were in your case would pick up a either set of Vortec Iron Heads or even the Etec Heads from Edelbrock. Either heads will out flow your current heads and give you a little more power and then I would definitely rebuild the engine and put either a TH350 or a 4L60 Tranny and get rid of that damned powerglide !! For street use the Powerglide is crap but either a 4L60 (700R4) or TH350 will be better for the street and give you a little better gas mileage !! Here is my Engine Setup and my gas mileage just sucks but hell this is what I get for building a 350 like this 91 350 (non roller block but can accept the OEM Roller Cam and Lifters), L79 66 Corvette Cam, 3890462 Corvette Fuelie Heads, Flat Top Piston, Carter 9635 625 CFM Electric Choke, Edelbrock Performer, accell HEI, MR Gasket Headers(Old headers but were free) and I am running around 10.5 - 11.5 somewhere around there. And I am running approximately 350 HP and I have to run nothing less then 91 Octane (had to back my timing off just to run 91 effeciantly) and I am running TH400 Tranny w/ 3.73:1 Gear Ratio. My Gas mileage blows but I will not change my heads unless I have to but if I were running 305 Heads, I would get me a set of Vortecs in a heartbeat!! ------------------ Truck #1 68 Chev LWB Fleet w/ Wood Floor (Sucks Gas and Hauls Ass!) and in process of Body Work... Truck #2 1994 GMC Sierra SL w/ 4.3L Vortec V6, 4L60E Auto!! __________________ 1968 C10 Truck LWB Fleetside 1968 C10 Truck SWB Stepside 1994 K2500 Ext Cab Fleetside 2008 Honda Civic Si lease

05-21-2002, 02:01 PM	#1
Bandit Registered User Join Date: Feb 2002 Location: Saskatchewan, Canada Posts: 23	Engine buildup!!! I have purchased a set of heddman headers, an Edelbrock Performer intake, and a Edelbrock performer 600cfm manual choke carb. The truck is a 69 GMC 910 with a 350 in it. Currently, it has the stock intake, 490cfm Quadrajet, RV cam, 305 heads ( I know they suck! ) 10:1 pistons .030 over, and yes, a Powerglide tranny! With installing my new purchased equipment, do you guy's think there will be a noticable increase in power? the truck has dual exhaust of course, but it is like, 2 inch pipe, is this REALLY bad or will it be okay? Must the engine be lifted to install heddman headers or will they fit in with the engine on the mounts? Any help is much appreciated, If you have any tips on the intake and carb, please share! I need all the help I can get!!! Bandit

05-21-2002, 02:13 PM	#2
Low69CST Registered User Join Date: May 2000 Location: Frankfort, Kentucky, USA Posts: 2,163	you can install the headers with the motor in. The 2 inch pipe should be OK, not ideal though. ------------------ '69 CST Short fleetside Lowered, 400 small block, 700R4, 4 wheel disc brakes, front & rear sway bars See my truck at: http://www.geocities.com/low69cst/ Student at the University of Kentucky. Feel free to message me on AOL, SN- SS95ZQ8 My Dad's projects: 72 Short Fleet 4x4 Chyenne Super 72 Long Fleet 4x4 Chyenne Super Both 350 autos restored original __________________ '69 CST Short fleetside Lowered, 400 small block, 700R4, 4 wheel disc brakes, front sway bar & rear camaro sway bar (in progress) '87 V10 4x4 Short Fleetside Quad Suspension and Dual Tanks

05-21-2002, 02:57 PM	#4
Bandit Registered User Join Date: Feb 2002 Location: Saskatchewan, Canada Posts: 23	Thanks for the replies guys! What would be your guess as far as horsepower gain from the header, intake, and carb installation. The Performer intake as I believe is better for torque than it is horsepower, which is good with the powerglide. Would a 40hp gain be too generous? Thanks again! Bandit

05-21-2002, 03:28 PM	#5
Bandit Registered User Join Date: Feb 2002 Location: Saskatchewan, Canada Posts: 23	I went ahead and got the casting number off the block, it is 3970010 which is either a 68 327 or a 69-78 or something 350. The guy I bought the truck off said the engine was a four bolt main from a 73 z-28 and with checking the other numbers, I came to the conclusion he wasn't bullsh!ting me. The engine stock was 245 hp, mind you, the heads had been changed as earlier stated to 305's. How much power loss would there be from these heads being installed. My comression ratio is about 10.5:1 i figure because I have to run premium all the time. Does high compression mean higher hp, or just a cleaner burn?

05-21-2002, 03:45 PM	#6
67Fleetsidedream Wiseass secured himself a BAN Join Date: Nov 2000 Location: MOON!!! Posts: 2,282	Just a note. Having 305 heads on a 350 will cause detonation or "pinging". Get yourself some 350 heads pretty soon or start running 110 octane. Detonation will kill a engine in a heartbeat. Been there, done that and got a T-shirt. Ben ------------------ 67 Fleetside Custom C-10 SBC 350 .030 9:1 comp. Comp Cams Extreme Energy XE256H-10 Carter AFB 600 Edlebrock performer intake Screw in rocker studs Oversize valves Scat 350 crank Everything balanced within one gram. Marine grade plywood bed(looks awsome)

05-21-2002, 05:32 PM	#8
Bandit Registered User Join Date: Feb 2002 Location: Saskatchewan, Canada Posts: 23	Why do the 305 heads cause detonation, or pinging? Don't they just boost compression due to the smaller combustion chamber? Anyways, I just pulled the oil pan off the engine and to my suprise I found not one, but two ends of dipsticks. They have been brocken off right around the full mark. Has ANYBODY ever seen this before????? Also there were three self locking nuts off that plate that is attached beneath the crank. Most of these nuts were loose and I'm sure glad I pulled the pan off!! P.S. What is the best octane boost? I usually use Super 104+ and it seems alright, but all suggestions are appreciated! Bandit

05-21-2002, 06:22 PM	#9
Bandit Registered User Join Date: Feb 2002 Location: Saskatchewan, Canada Posts: 23	Hey all, I'm putting in a new front and rear seal and I need some assistance on installing them. What kind of silicone should I use etc.?

05-21-2002, 07:00 PM	#10
Bandit Registered User Join Date: Feb 2002 Location: Saskatchewan, Canada Posts: 23	back to the top

05-21-2002, 11:52 PM	#12
Bandit Registered User Join Date: Feb 2002 Location: Saskatchewan, Canada Posts: 23	It's the kind of thing that I put 12k miles on in the summer, park it for the winter. I would like it to have better torque for off the line, but I don't plan on having it see over 5000 rpm. Headers are more or less for sound and gas mileage.

05-22-2002, 01:36 AM	#15
Bandit Registered User Join Date: Feb 2002 Location: Saskatchewan, Canada Posts: 23	Hey DMNall, What are your RPM's at 65 mph??



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05-22-2002, 10:17 AM	#16
Tim Rich Registered User Join Date: Apr 2002 Location: Kennesaw, GA Posts: 56	The pinging comes from the higher compression, which is what higher octane prevents. That's why higher compression engines require premium gas, and why premium gas is a waste of money unless you need it. Glad my truck doesn't need premium - $1.11 a gallon's bad enough. ------------------ Tim Rich Kennesaw, GA 72 Stepside 65 Must@ng __________________ Tim Rich Kennesaw, GA 72 Stepside 65 Must@ng

05-22-2002, 11:20 AM	#17
busterwivell Registered User Join Date: Jan 2002 Location: Sahuarita, AZ USA Posts: 2,033	$1.35 here. The Studebaker has 10:1 flattops, roller rockers, dart heads, and needs 91 octane. Paid 189.9 per gallon outside DelMar last month. Glad the 700R and 3:55's let me get 23 MPG. ------------------ 56 Studebaker 2 dr Wagon 66 Chevelle 2 dr 4 speed 71 C30 Longhorn 86 Monte Carlo SS 96 Tahoe __________________ Bill - Tucson, AZ 47 Chevrolet 2 dr sedan 56 Chevrolet 210 2 dr sedan 66 Chevrolet Malibu 2 dr 4 speed 71 Chevrolet C30 Longhorn 86 Chevrolet Monte Carlo SS (Sold) 01 Chevrolet Tahoe IM - BUSTERWIVE@aol.com

05-22-2002, 12:42 PM	#18
Bandit Registered User Join Date: Feb 2002 Location: Saskatchewan, Canada Posts: 23	The thing is, My gas mileage is great with 22-23 mpg. I rev 3100 in the 65-68 range with the two speed and what I believe are 3.23 gears. I've been told that my rpm's sound too high for them to be 3.23's. People always say it sounds more like 3.73's. Anyway, what kind of gas mileage increase can I expect from adding the headers intake and carb. I'd like to see 25, is this outrageous?? Bandit

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