Will a pre 1987 350 Block work with 91 5.0 manifolds

[Spivy30]

I have been given a complete pre 1987 mercruiser 5.7 that is brand new still on the merc crate. I have a 91 5.0 alpha gen 1 with a cracked block and am wondering if this motor would work? I would understand if I had to tansfer some parts from the 5.0 to the 5.7 I basically just want to make sure my exhaust manifold will fit on these heads.

 

[Don S]

Re: Will a pre 1987 350 Block work with 91 5.0 manifolds

The exhaust manifolds are exactly the same. But if you have a cracked block on your old engine from freeze damage, you can bet the manifolds and risers are in the same condition.
I for one, would NEVER put old manifolds on a new engine.

 

[chiefalen]

Re: Will a pre 1987 350 Block work with 91 5.0 manifolds

Ask the guy who gave you the motor if he has the rest for free.

Right here at the site i bet sells the parts you need.

 

[Gary H NC]

Re: Will a pre 1987 350 Block work with 91 5.0 manifolds

Yep,New motor would be new manifolds for sure.Why chance it?
The peace of mind all new parts would give you would be worth the cost.

Gave you a new motor in the crate? Thats awesome!!

You can get the complete new set for around 500...http://www.ebasicpower.com/exhaust/merex.php

 

[chiefalen]

Re: Will a pre 1987 350 Block work with 91 5.0 manifolds

There you go again spending other peoples money, ha.

Thats a good price.

The whole thing in one package, nice.

 

[Spivy30]

Re: Will a pre 1987 350 Block work with 91 5.0 manifolds

so the motor should bolt up then?

 

[Gary H NC]

Re: Will a pre 1987 350 Block work with 91 5.0 manifolds

Should be no problem...

 

[Spivy30]

Re: Will a pre 1987 350 Block work with 91 5.0 manifolds

The old 5.0 had a brand new ignition system put it last year, will the whole thunderbolt system transfer over? I'm pretty sure the 5.7 has points

 

[chiefalen]

Re: Will a pre 1987 350 Block work with 91 5.0 manifolds

Did someone tell you, it won't fit?

Cause the ignition is the same.

Timing might be different.

Starters the same also, alternator.

 

[Spivy30]

Re: Will a pre 1987 350 Block work with 91 5.0 manifolds

Yeah, somebody told me the 87-95 blocks will only work with my motor and I didn't really believe them. I always thought a small block was a small block

Thanks everybody for your help!

 

[bomar76]

Re: Will a pre 1987 350 Block work with 91 5.0 manifolds

The problem is you never asked the right question.
The pre 87 engines use a two piece main seal and a different diameter flywheel than the 87 up one piece rear main seal blocks.
What he has I dunno 'cause I don't want to try to decipher the OP's original post, and he asked the wrong question, but if he is trying to mix one piece and two piece main seal blocks he is gonna run into a few issues....

 

[Spivy30]

Re: Will a pre 1987 350 Block work with 91 5.0 manifolds

Ok, would I be able use a pre 1987 350 motor with a 1991 5.0 Alpha Gen 1 setup? What issues may I run into?

 

[rodbolt]

Re: Will a pre 1987 350 Block work with 91 5.0 manifolds

will it fit?
yes,
however like Bomar pointed out you will have to use the correct flywheel and starter for the pre-87 crankshaft.
you may also need to block off the mechanical fuel pump mount if your 5.0 used an electric fuel pump.
most of it is pretty straight forward but make careful notes of what parts were used for future replacement references.

 

[Spivy30]

Re: Will a pre 1987 350 Block work with 91 5.0 manifolds

Which bellhousing would I use? Any electrical issues that would come up?

 

[Bondo]

Re: Will a pre 1987 350 Block work with 91 5.0 manifolds

Which bellhousing would I use?

Ayuh,... It don't matter,.. They should be the Same...

It's the Flywheel, Starter,+ Coupler that'll possibly be a Problem...

 

[Spivy30]

Re: Will a pre 1987 350 Block work with 91 5.0 manifolds

So I should use the flywheel starter coupler from the 5.7?