So I have spare engine that I am wanting to build before summer. It is a 140 20 bolt block. I have read that 140 is a slightly taller deck and will cause my compression to be lower but if this works i can always deck the block and heads. I am having a hard time finding anything that says its for 84 85 turbo engines. So I am wondering will a set of JE's Cp or even stock 109 stuff, for 86 87 pistons and rods work. Also is the crank the same for all 4 years 84-87. . But not many people are clear about what works with what. I get a they should or I think so. I know there are a lot of fast guys on here who can give me some hope.
85 engine build will 87 internals work?
- Thread starter matt921
- Start date
The cranks are the same. You would need a taller compression height to get the same CR. I don't rec milling the deck or heads more than a cleanup to be sure they are flat. Order the Pistons with the correct compression height and dish to get the CR you wabt
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CzyKats44
This is the way.
- Joined
- Jun 28, 2014
Theoretically, could you "top swap" like the 3800 guys (L36/L67 from heads up), like a HA short block with 86-87 Heads and up?
I'll expand this just a bit. In 77.5 GM came out with the even fire Buick V6 engine. The only differences being the bore size between the blocks, so the odd balls are the 3.2 and 4.1 engines in RWD. All the heads will bolt on but the 79 up heads are high port heads and are the ones that are preferred for all the turbo and performance application. All of the internal parts will interchange except for the pistons of the 3.2 and 4.1. The preferred cranks are out of the turbo and 4.1 applications. None of the FWD cranks blocks, and rods will bolt on or fit in the RWD applications without some sort of adaptation. The FWD heads like the TTA use and the series II and III heads, will bolt directly on, but accessories like intake and exhaust will have to be fabricated for the series II and III, and the TTA parts will need to be used if using series I heads.
CzyKats44
This is the way.
- Joined
- Jun 28, 2014
I apologize for not being clear. I didn't mean swapping and FWD tops to older blocks (although it's interesting on what fits and what doesn't ).
A basic W body upgrade thing was to take the heads up from the S/C model and put them on the NA. Curious if the same idea works with G-Body 3.8s.
If I understand correctly, the RWD 3.8 short block will accept all 78-88 N/A, HA and Intercooled top ends with minimal block mods just piston height for proper compression.
*Not trying to hijack your thread Matt, I hope there is relevance at least from the top end.
A basic W body upgrade thing was to take the heads up from the S/C model and put them on the NA. Curious if the same idea works with G-Body 3.8s.
If I understand correctly, the RWD 3.8 short block will accept all 78-88 N/A, HA and Intercooled top ends with minimal block mods just piston height for proper compression.
*Not trying to hijack your thread Matt, I hope there is relevance at least from the top end.
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The 77.5 up RWD short block would work with the 79-88 RWD heads, and the 78 and earlier are low port so the intake won't work, but the 77.5 and earlier engines won't work in any way shape or form. Remember that this design has been around since 1962 and has had a few changes since then.
If someone made an intake and headers for the series II/III heads as well as a cam for the RWD block, this would make a great combo.
No man your not hijacking you asking these is helping me out a lot.
