87 7.4 tbi

[f_ford_custom]

hello all,
I have an 87 R30 CC dually 454 tbi, granny 4, and stock rear. I am about the 4th owner, was told 45k original miles. still had dry rotted 7.50R16s when picked up. I got it as a package with a 32' 5th wheel trailer.

known mods - flex fan, larger oil cooler (I don't think gm put one on that's 1/3 sqft of the radiator), oil pump? (pres NEVER comes DOWN to the scale on the guage-60), and the optional 235/80R16s - It has a gooseneck 2 5/16 ball mount in the bed, w/adapter on TT. custom 3" duals, aftermarket cats

That's about all I know about the truck.

Questions
does this sound right? compression 118-126 - vac @ idle (900) 17"
Is stock TBI worth saving? need TPS, parts store says special 87-88 454 only-will not give back money if 350 tps doesn't work-discontinued 1991
I need it mostly for towing, and gross about 16k
I have a holley 80555c NIB from a mopar that I sold; and several HEI dizzies, would I be better off rebuilding one, and going carbed? I know, regulator to fuel lines, oil press kill switch to fp.
What would be a good engine combo? Economy>Torque>Loud -cruise rpm ~1950@40-2700@70
Rear axle? Dana 70-right? has 14 bolts, cover says dana, ring gear says dana 4.11
Headers or manifolds? entire exhaust is rotted out - emissions exempt co, plus registered at above 8600 GVWR.

I'll think of more, or clarify myself later. I've been up 52 hours, time to sleep. Ill check back tomorrow. Thank you for your time.

[pig rig]

I have an 88 with the tbi 454 and I love it Ive done a lot of stuff to mine

working with a ecm controled engine was(still is) a learning curve for me but thats part of what I like about it

the biggest thing to remember is when your at a parts store is to make sure they hear you say its an R model

[f_ford_custom]

I like the TBI setup, I'm just not sure of the life expectancy of the computer. I know fords are 18 years, but have seen 86 efi engines w/ no problems. I would like to keep the tbi setup, it is kinda nice to get 12 mpg empty with a direct drive big block, now I get 8. While towing, economy is no concern, I always turn 15 or better, since I can actually let off the gas completely.

I wish someone knew if the compression and vacuum numbers sounded right for a stock engine.

I would kinda like to build the engine later, 9.5 compression, tight roller cam - am thinking of COMP XR264HR, summit headers, dual 3" with stacks - need a flatbed first-w/ tire carrier and toolboxes. I was also thinking of putting either an RPM air-gap or 7522/ c-66 air gap- using a 5.7L TBI unit i have lying around and megasquirt. I tossed around the idea of a blower, but I like my hood.

The Dana 70, I think, that's whats standard on duallies, right? I have 4.11s, and the tallest I can find is 3.73s, but I do tow, and usually cruise about 52, which is 2100 rpm, I think the $375 would be better spent elsewhere. But I have seen that 1 1/2 tons had gm 14 bolts? That opens up 3.42s, which would be worth $280, I don't know the difference in axles. Mine IS a FULL FLOATER open carrier, and I would like a selectable locker. That WOULD be worth $500. It is embarrassing to get stuck in a concrete parking lot in the only pot hole.

Manifolds vs Headers- Torque production, fuel economy, ease of use - How much Tq and econ am I giving up w/ manifolds? With locking fasteners, and ceramic coating, how much more maintainance will the headers be? I have heard all BBCs benefit from headers, even tow rigs. How true is this?

Sorry about all the questions so soon, I will be leaving 7/3 @ 2200 est and will not be back B4 Saturday, if lucky. Thanks, you guys seem really knowledgeable. it's just I cannot find the answers to the questions I have in previous posts. Thanks again. GOD BLESS Y'ALL

[clinebarger]

Originally Posted by f_ford_custom

The Dana 70, I think, that's whats standard on duallies, right? I have 4.11s, and the tallest I can find is 3.73s, but I do tow, and usually cruise about 52, which is 2100 rpm, I think the $375 would be better spent elsewhere. But I have seen that 1 1/2 tons had gm 14 bolts? That opens up 3.42s, which would be worth $280, I don't know the difference in axles. Mine IS a FULL FLOATER open carrier,

Dana 70s are rare under Chevy trucks, Dodge used the most, followed by Ford, Then Chevy (All that I know of were Cab & Chassis trucks)

The "tallest" or the lowest numerical gear is 3:54 to 1 in a Dana 70.

[Matt Man]

Originally Posted by clinebarger

Dana 70s are rare under Chevy trucks, Dodge used the most, followed by Ford, Then Chevy (All that I know of were Cab & Chassis trucks)

The "tallest" or the lowest numerical gear is 3:54 to 1 in a Dana 70.

my truck has a dana70hd...

[f_ford_custom]

Sorry, got dates mixed up. I'm leaving in a few hours. also asked around in 'engines' section-no responses. Looks like the regulator to use is the Mallory 4309, I think I can mount it on the firewall and run a rubber line to a tube mounted on the valve cover to the carb, that should keep things cleaned up pretty nice. Although, keeping the tbi would be nicer. Also, does NE1 know if a 350 tps will work w/ my computer? The neighbor said he has one NIB he would sell for $5. I'll wait and see when I get back.... Maybe I can get another good run and be back Friday... Hay TX, CO, order lots of stuff from GA! I love western runs, makes up for that I95 crap. No offense, but I loose a half day driving and 6 hours sleep every weekend.

GOD BLESS, I'm out

[rfmaster]

Originally Posted by f_ford_custom

hello all,
I have an 87 R30 CC dually 454 tbi, granny 4, and stock rear. I am about the 4th owner, was told 45k original miles. still had dry rotted 7.50R16s when picked up. I got it as a package with a 32' 5th wheel trailer.

known mods - flex fan, larger oil cooler (I don't think gm put one on that's 1/3 sqft of the radiator), oil pump? (pres NEVER comes DOWN to the scale on the guage-60), and the optional 235/80R16s - It has a gooseneck 2 5/16 ball mount in the bed, w/adapter on TT. custom 3" duals, aftermarket cats

That's about all I know about the truck.

Questions
does this sound right? compression 118-126 - vac @ idle (900) 17"
Is stock TBI worth saving? need TPS, parts store says special 87-88 454 only-will not give back money if 350 tps doesn't work-discontinued 1991
I need it mostly for towing, and gross about 16k
I have a holley 80555c NIB from a mopar that I sold; and several HEI dizzies, would I be better off rebuilding one, and going carbed? I know, regulator to fuel lines, oil press kill switch to fp.
What would be a good engine combo? Economy>Torque>Loud -cruise rpm ~1950@40-2700@70
Rear axle? Dana 70-right? has 14 bolts, cover says dana, ring gear says dana 4.11
Headers or manifolds? entire exhaust is rotted out - emissions exempt co, plus registered at above 8600 GVWR.

I'll think of more, or clarify myself later. I've been up 52 hours, time to sleep. Ill check back tomorrow. Thank you for your time.

What ever you do stay away from a carburetor - that 454 was setup to run with TBI and it will run very well for many more miles. With regard to TPS you have couple of choices. Original TPS is a right angle style with wire harness plug connecting horizontally (OE 17111787). This is a very common TPS (used on many 87-90 TBI passenger cars).

As an alternative, if you have a vertical clearance above TPS (for example after market intake from K&N ) OE 17112368 vertical plug style can be used. Both parts are electrically identical and will bolt to throttle body (done this here on my latest project).

If you chose to go with headers you'll have to switch from a single wire O2 sensor to a heated version - for example Delco AFS74. Cast Iron manifolds keep O2 hot which is required for O2 operation. A simple relay circuit should provide power to O2 heater.

A true dual exhaust (2-1/2") with a cross over pipe and pair of delta 50's will wake up that otherwise sleepy giant, but it will keep it mild enough to be tolerable. Going to 3" duals - other than bragging factor yield very little in terms of intended performance (towing).

//RF

[ratty 46]

rfmaster ... why steer him away from the carb set up??

I'm right in the mix of converting my '87 crew/454/TBI to a Carb, intake, "basic" HEI, MSD, mechanical fuel pump & have run MANY 454's with this combo. Aside from a little "extra" wiring under the hood it's not all that much an issue.

I'm also changing the single flowmaster muffler to a real dual set up. Air in .... Air out ...

I bought the truck out of Lake Elsinore, Ca. & it came with all the smog equipment installed. These are all being removed as here in GA. they are NOT required. One of the board members is getting all the removed items - including the computer.

Your thoughts ......

Ratty 46

[rfmaster]

Originally Posted by ratty 46

rfmaster ... why steer him away from the carb set up??

I'm right in the mix of converting my '87 crew/454/TBI to a Carb, intake, "basic" HEI, MSD, mechanical fuel pump & have run MANY 454's with this combo. Aside from a little "extra" wiring under the hood it's not all that much an issue.

I'm also changing the single flowmaster muffler to a real dual set up. Air in .... Air out ...

I bought the truck out of Lake Elsinore, Ca. & it came with all the smog equipment installed. These are all being removed as here in GA. they are NOT required. One of the board members is getting all the removed items - including the computer.

Your thoughts ......

Ratty 46

Very simple - Carburetor + Carbed HEI will never produce overall fuel efficiency that a TBI with a free flowing exhaust setup will yield. With ECM controlling both spark and fuel under a multitude of operating conditions that carburetor can not match. Secondly, I have probably taken over 100 engines apart over the last 25 years. All carburetor engines showed noticeable bore ridge, while majority of EFI engines (even high millage) showed very little bore wear! Why? EFI engines tend to run in close loop (14.7:1) most of the time and there no excess fuel leaking down the cylinder walls washing away engine oil.

//RF

[ratty 46]

Thanks for the (your) insight RF .... but due to my limited knowledge & my inability to adjust to the "bell curve" of injection .... I'm old fashion & can fiddle with the carb, HEI, intake & MSD box a whole lot better than I can the other, I'll continue & complete my transformation. That's just me.

I do, however, think its a viable alternative to the injection program. Hopefully I won't keep this truck 25 years to see the negative side of my work.

Consider the alternative f ford custom.

Ratty 46

[rfmaster]

Originally Posted by ratty 46

Thanks for the (your) insight RF .... but due to my limited knowledge & my inability to adjust to the "bell curve" of injection .... I'm old fashion & can fiddle with the carb, HEI, intake & MSD box a whole lot better than I can the other, I'll continue & complete my transformation. That's just me.

I do, however, think its a viable alternative to the injection program. Hopefully I won't keep this truck 25 years to see the negative side of my work.

Consider the alternative f ford custom.

Ratty 46

Ratty - to each its own. We all choose what what we do. For me it was a logical choice since I have in-depth background in electronics and love for things mechanical! So, I tend to add electronics to old iron without changing its character, subtly make it better.

Good luck with your rig.

//RF

[ratty 46]

That is where I fall short .... the electronics part. I wish my skill set was a bit more in- depth in that area as I might be running down the same road as you.

Given my limited knowledge in FI or specific TBI I'm trying to make the best of my knowledge without getting in to much trouble.

I wish guys like you .... lived closer.

Thanks.

Ratty 46

[f_ford_custom]

Just got back in town today about 18:30 est. I want to keep the tbi, but what do I look up that part under @ Autozone? Will my truck w/350 work? It's even right angle. The book just said my truck called for an 87-88 only part that went out of production in 1991.

How much can the factory computer handle, engine mod wise? I was thinking of FT pistons (to net 9.5:1 CR) and a COMP XR264HR cam w/ roller tipped r/as. Would this be possible?

If I switch from 4.11s to 3.54s, what kind of trade off would I make? fuel mileage v towing capabilities?

OK, I'm out. Will be back several times tomorrow B4 going out 7/12 about 0530. Thank you very much and GOD BLESS!

[rfmaster]

Originally Posted by f_ford_custom

Just got back in town today about 18:30 est. I want to keep the tbi, but what do I look up that part under @ Autozone? Will my truck w/350 work? It's even right angle. The book just said my truck called for an 87-88 only part that went out of production in 1991.

How much can the factory computer handle, engine mod wise? I was thinking of FT pistons (to net 9.5:1 CR) and a COMP XR264HR cam w/ roller tipped r/as. Would this be possible?

If I switch from 4.11s to 3.54s, what kind of trade off would I make? fuel mileage v towing capabilities?

OK, I'm out. Will be back several times tomorrow B4 going out 7/12 about 0530. Thank you very much and GOD BLESS!

On a TPS issue - Have your local Aurozone look-up TPS for 1990-88 Camaro 5.0L (E) 305" TBI: OE 17088028; 17089062, 063, 17111787, Walker 200-1045 or Duralast TPS108 or EC1035

XR264HR is a great cam for towing, except that XR264HR-13 (01-412-8) is designed for OE roller cam engines - 454CID 1996-1999. Your 87 has conventional flat tappet lifters and can not use aforementioned cam. Instead look into 260AH (11-302-4) which is compatible with stock ECM programming and torque converter. - read Comp Cam data sheet on this cam!

If you are a bit more adventurous and willing to tune your ECM (or use tuner services ) look into X4 262H (11-235-3) which gives you more mid range power for HD towing with 4.11 gears. When you get back - ask away.

//RF

[Mr.Chevy4x4]

Check out this web site: http://www.tbichips.com

This guy has a lot of good information and can burn a chip to work with your mods. You might have to upgrade your fuel pump and fuel pressure regulator to keep up with all of that new horsepower. There are also companies that will hone the throttle body to increase the CFM whick you will need with the mods. I would keep the peanut port heads. If you put big free flowing heads on it you will kill the low end torque. I would just do some pocket porting to the original heads and maybe gasket match the intake to the ports. An aftermarket aluminum intake will help also. Make sure the cam you decide on has at least 112 degree lobe separation angle (LSA). Any less and you will run in to tunability issues with the TBI.

I have had 2 TBI 454's, and loved both of them. They can be powerhouses with a few mods.

Just my $.02.

Mike

[grinch4om]

the gear swap will not improve mileage enough to matter. I would invest in a good aftermarket add on over drive. research you TBI. I have converted a TBI engine to carb and standard HEI but only because it was a swap deal. Injection is always more efficient because stochiometric ratio can be maintain through out the rpm range. I would check Edelbrock, they have lots of research data on TBI mods and that info is invaluable for you. 3" single exhaust with shorty headers, hi flow cat and a 2 chamber flowmaster would be sufficient but if you can get dual 2.5" and 2 converters, that works too. I did the single as described and added 2-3 MPG and boosted low end grunt. It sounded good without being obnoxious