Just want to make sure before I dig in... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Chevelle454 · 08-31-2004, 10:01 PM

I am going to put the 355 short block from my '72 C20 into my 1984 Caprice. The caprice has a 305 right now. Everything on the Caprice is original, I am only changing the 305 block to a 350. Will the Caprice heads and manifolds bolt right up to my '72 block??? I need to make sure before I get into it...

Thanks,
Scott

Chevelle454 · 08-31-2004, 10:22 PM

ttt

*Randy70C-10* · 08-31-2004, 10:24 PM

Yes, but your heads only have 1.72 intake valves, you won't get much power from them.

Chevelle454 · 08-31-2004, 10:30 PM

I should get more than the stock 305, though, right? This 350 is bored .030 over with a crane cam (.440 lift int/exh, 266 duration). I also have an Edelbrock Performer intake and a new Performer series carb... It should be better than a stock 305 with all smog equipment still intact. The 305 only made 150hp, 240ft/lbs when it was brand new. I know the heads hold me back, but how much really?

*Randy70C-10* · 08-31-2004, 10:33 PM

That's a decent size cam. Your engine will do ok, but you should try to find a pair of heads with at least 1.94's in them. Your engine will perform much better if it can breathe.

Longhorn Man · 09-01-2004, 12:45 AM

I did the 305 heads on a 350 and it sucked. Compression was too high, and I was out run by a 292 inline truck...that was embarasing.
Put 882 heds with 194 intake valves and it was like a whole new motor.

68w/sbc406 · 09-01-2004, 12:51 AM

no replacement for displacement, except for air flow. i had a guy tell me that if he took 5000 bucks and dumped 4500 into a bottom end and 500 into the top, he would get killed buy a guy that took 5000 and put 500 into a bottom end and 4500 into heads

Chevelle454 · 09-01-2004, 07:07 AM

Well, would it be a better idea to just use the 305 block and put on the new intake and carb? Would this put out more than the 350 block with the cam? I don't want to switch blocks if it's only going to be a 10-20 hp difference...

dubie · 09-01-2004, 09:05 AM

I am running 305 heads on my 350 and it's not so bad. It all depends on what you want out of your engine. I wanted a nice daily cruiser that had a lot of low end torque and thats what I got with these heads. It's got a ton of low end torque but will not be able to breathe much past 5000 rpms. It's a very responsive engine on the pedal thats for sure, but for 12 months out of the year type driving and better overall performance, I would get some 882 heads. I plan on swapping mine out in a couple years when I decide to swap the tranny so we can take it and the 58 on longer drives

Chevelle454 · 09-01-2004, 09:24 PM

Sounds good, my cam is only good to about 4600 anyway... I'll get started...

08-31-2004, 10:01 PM	#1
Chevelle454 Registered User Join Date: Aug 2003 Location: MN Posts: 380	Just want to make sure before I dig in... I am going to put the 355 short block from my '72 C20 into my 1984 Caprice. The caprice has a 305 right now. Everything on the Caprice is original, I am only changing the 305 block to a 350. Will the Caprice heads and manifolds bolt right up to my '72 block??? I need to make sure before I get into it... Thanks, Scott __________________ 1972 C10 1972 C20

08-31-2004, 10:22 PM	#2
Chevelle454 Registered User Join Date: Aug 2003 Location: MN Posts: 380	ttt __________________ 1972 C10 1972 C20

08-31-2004, 10:30 PM	#4
Chevelle454 Registered User Join Date: Aug 2003 Location: MN Posts: 380	I should get more than the stock 305, though, right? This 350 is bored .030 over with a crane cam (.440 lift int/exh, 266 duration). I also have an Edelbrock Performer intake and a new Performer series carb... It should be better than a stock 305 with all smog equipment still intact. The 305 only made 150hp, 240ft/lbs when it was brand new. I know the heads hold me back, but how much really? __________________ 1972 C10 1972 C20

09-01-2004, 12:51 AM	#7
68w/sbc406 Got Light Emitting Diode? Join Date: Apr 2004 Location: Newberg, OR Posts: 2,485	no replacement for displacement, except for air flow. i had a guy tell me that if he took 5000 bucks and dumped 4500 into a bottom end and 500 into the top, he would get killed buy a guy that took 5000 and put 500 into a bottom end and 4500 into heads __________________ 1968 1/2 ton 2wd lwb 6 lug disc and bags up front. Next c notch and rear bags '02 Chevy Silverado LT ext cab short bed 2WD 5/7 drop on 22's(the family car) 1993 Cherokee work ride/weekend wheeler

09-01-2004, 07:07 AM	#8
Chevelle454 Registered User Join Date: Aug 2003 Location: MN Posts: 380	Well, would it be a better idea to just use the 305 block and put on the new intake and carb? Would this put out more than the 350 block with the cam? I don't want to switch blocks if it's only going to be a 10-20 hp difference... __________________ 1972 C10 1972 C20

08-31-2004, 10:24 PM	#3
Randy70C-10 Account Suspended Join Date: Mar 2001 Location: Virginia Beach, Va. U.S.A. Posts: 15,320	Yes, but your heads only have 1.72 intake valves, you won't get much power from them.

08-31-2004, 10:33 PM	#5
Randy70C-10 Account Suspended Join Date: Mar 2001 Location: Virginia Beach, Va. U.S.A. Posts: 15,320	That's a decent size cam. Your engine will do ok, but you should try to find a pair of heads with at least 1.94's in them. Your engine will perform much better if it can breathe.

09-01-2004, 12:45 AM	#6
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	I did the 305 heads on a 350 and it sucked. Compression was too high, and I was out run by a 292 inline truck...that was embarasing. Put 882 heds with 194 intake valves and it was like a whole new motor.

09-01-2004, 09:05 AM	#9
dubie Registered User Join Date: May 2000 Location: Flin Flon, Manitoba, Canada Posts: 8,853	I am running 305 heads on my 350 and it's not so bad. It all depends on what you want out of your engine. I wanted a nice daily cruiser that had a lot of low end torque and thats what I got with these heads. It's got a ton of low end torque but will not be able to breathe much past 5000 rpms. It's a very responsive engine on the pedal thats for sure, but for 12 months out of the year type driving and better overall performance, I would get some 882 heads. I plan on swapping mine out in a couple years when I decide to swap the tranny so we can take it and the 58 on longer drives __________________ My name's Tim and I'm a truckaholic My 56 Chevy shop truck build http://67-72chevytrucks.com/vboard/s...d.php?t=562795

09-01-2004, 09:24 PM	#10
Chevelle454 Registered User Join Date: Aug 2003 Location: MN Posts: 380	Sounds good, my cam is only good to about 4600 anyway... I'll get started... __________________ 1972 C10 1972 C20



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