jimmy'sjimmy
1/2 ton status
Wondering what size the stock TBI heads are? I thought they were 64cc but I was talking to a guy at a machine shop and he said they are most likely 76cc. Anyone no for sure?
CK5
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TBI Heads cc?
- Thread starter jimmy'sjimmy
- Start date
btolenti
1/2 ton status
according to Pace, the replacement crate motor has 64cc heads....
http://www.paceparts.com/index.asp?PageAction=VIEWPROD&ProdID=17668
But I too have heard about 76cc heads on a TBI as well....
http://www.paceparts.com/index.asp?PageAction=VIEWPROD&ProdID=17668
But I too have heard about 76cc heads on a TBI as well....
jimmy'sjimmy
1/2 ton status
Is there anyway to tell for sure? I found some other sites that say these are 76cc no matter what. just want to be sure before i buy this short block or my compression will be way too hi.
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btolenti
1/2 ton status
the only sure fire way to know is to check the head casting number in a part's book. Do you have the casting number?
sled_dog
1 ton status
350s had 76ccs
The heads I had were 64s, so maybe 305 heads, but all I know is they made my TBI406 a MONSTER!!!!
TallCowGirl
Registered Member
1987-88 EFI Swirl Port Head
Hi There...I had a 383 engine made from an 1987 TBI 350. The head casting number was 14102191. The engine builder thought the head chamber volume was 76cc's, but (after lots of research and asking people) it turns out that 14102191 or 14102193 heads have a 64cc chamber volume.
Hope this helps,
Diana
Hi There...I had a 383 engine made from an 1987 TBI 350. The head casting number was 14102191. The engine builder thought the head chamber volume was 76cc's, but (after lots of research and asking people) it turns out that 14102191 or 14102193 heads have a 64cc chamber volume.
Hope this helps,
Diana
NateInChandler
1/2 ton status
Actually im not so sure that 350's all had 76cc heads, some of the 90-93 TBI motors were rated at 9.5:1 compression and that isnt gonna happen with 76cc heads and a flat top piston. I know my motor puts out almost 180psi in each cyl and its a bone stock 91 TBI Motor.
jimmy'sjimmy
1/2 ton status
casting # ends with 191
TBI heads are 76cc chambers, it's the vortec's that have 64cc chambers.
4X4HIGH said:
so do you want bigger or smaller???what is the main difference???
I'm assuming you're refering to chamber size. That all depends on what compression ratio you're looking to achieve. If you have 76cc heads and want more compression then going to a smaller chamber will achieve this but may not always be a good thing. Compression, cam, and induction all work together to form a package that will make torque and HP but changing one thing and not the other could be counter productive.
The 14102193 heads were 64cc. The 14102191 heads the I have are 76cc heads, with 1.95 intake valve and 1.5 exhaust. These are high torque 350 heads.
It's been awhile but i'm fairly sure the TBI engines were 58cc chambers.
The Chevy talk site is incorrect.
There are 58cc SP heads from the 305
The 14102191 heads are 76cc swirl ports
The 14102193 heads are 64cc swirl ports
Further research on the 191 heads
30mm×50mm intake port
34mm×34mm exhaust port
This is not confirmed
178 cfm intake
146 cfm exhaust
There are 58cc SP heads from the 305
The 14102191 heads are 76cc swirl ports
The 14102193 heads are 64cc swirl ports
Further research on the 191 heads
30mm×50mm intake port
34mm×34mm exhaust port
This is not confirmed
178 cfm intake
146 cfm exhaust
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350 TBI engines that had a non-overdrive T400 behind it had 76cc heads (8.75:1 compression). 350 TBI engines that had overdrive 700R, 4L60E, and later in 1991 4L80E transmissions...had 64cc heads (9:1 maybe higher compression). The 4-bolt main 76cc head TBI truck (with T400 trans) engine has been discontinued by GM, and the only GM Goodwrench crate TBI engine available anymore is the 2-bolt main with 64cc head.
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So im not near my truck atm..2100 miles away...but what do you think a 1996 tahoe had? Thats whats on my truck...
I believe 1996 was the first year of the Vortec engine, and Swirl Port TBI engines where history. I believe Vortecs are 96cc heads.
I believe your belief to be correct I have a 1st gen 96 Vortec 6 cyl. Currently building a 87 Swirl Port with 76 cc heads and semi dome top pistons. May attempt to find the original pistons that had a swirl top and went with the swirl port heads
I am not sure you should bother to rebuild that engine. You can buy a completely new GM Goodwrench TBI Swirl Port engine for about $1600. Rebuilding the engine you have could cost more.
