Early '86 engine replacement question

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Mar 4, 2013 | 06:45 AM

dacfan

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Racer

Joined: Oct 2010

Posts: 278

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From: Ware Shoals SC

Early '86 engine replacement question

After looking at several options on an engine rebuild of a early 1986 iron head L98 I think the most cost effective approach is a new GM crate motor. The "universal" 350 P/N GM 10067353 is about the same price as most rebuilt engines and with some sellers offering free shipping I think that's the way to go. I can then take my time rebuilding my old L98 in the garage. All info on this engine says it's only for vehicles up to 1985. My question is: Isn't this also a direct drop-in in a 1986 vette?
Being an iron head '86 isn't it pretty much the same as an '85 as far as matching up the intake and anything else in the engine bay?
Will computer and injectors all work fine without any mods?
I want to be able to drop it in, time it up and go.

Mar 4, 2013 | 07:27 AM

PAINTER MAN

Burning Brakes

Joined: May 2004

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From: Athens Ohio

I believe the 85 has a two piece rear main seal and the 86 has a one piece. It makes a difference when you bolt up the transmission.

Mar 4, 2013 | 08:18 AM

dacfan

Thread Starter

Racer

Joined: Oct 2010

Posts: 278

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From: Ware Shoals SC

Ahh.. I forgot about the crankshaft balance change between the old style two piece and the new style one piece. Would replacing the flexplate with one designed for the older two piece rear main solve the problem or is there more to it than that?

Mar 4, 2013 | 08:31 AM

cumbercr

Melting Slicks

Joined: Mar 2008

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From: Santa Maria, CA

The oil pans are also different on a 1 piece vs. 2 piece rear seal.

Mar 4, 2013 | 11:40 AM

John A. Marker

Le Mans Master

Joined: Mar 2004

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From: Dublin CA

You will also find the the cam is different in the crate engine.

I would consider going to a ZZ4 short block as the base and then build it up from there. This will give you a roller cam option.

Mar 4, 2013 | 02:47 PM

ejscarfo

Melting Slicks

Joined: Feb 2005

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From: Bay Shore, NY

Quote:

Originally Posted by John A. Marker

You will also find the the cam is different in the crate engine.

I would consider going to a ZZ4 short block as the base and then build it up from there. This will give you a roller cam option.

If you want to just "drop in" a motor while you rebuild yours, maybe you should consider a Jasper re-built motor. It would be a direct fit and you wouldn't have to worry about cams, oil pans, etc. The ZZ4 is a great engine and while doing research on the forum for my own engine build, many have used the ZZ4 as a replacement motor in their C4.