89 5.7 Mercruiser, Vortec Heads

[NHGuy]

If I want to do Vortec heads on my 89, 260 HP, 5.7 small block GM with center bolt valve covers what else do I need to make it all happen... and what else SHOULD I do to make it right?
Should I change the cam, do I have to? Do I have to do the intake manifold? Can my Rochester 4 bbl handle the increased air flow?
And can my through the prop exhaust handle the outflow?

I am aware that alpha 1 drives should not be hammered from a dead stop with this kind of power and I will keep the good lube in it.

This is a back burner plan, I'm just dreaming at this point.

 

[Bondo]

Re: 89 5.7 Mercruiser, Vortec Heads

what else do I need to make it all happen...

Ayuh,... The matching Intake Manifold....

All your questions have been answered here before,... Repeatedly....
Do a Search....

 

[John_S]

Re: 89 5.7 Mercruiser, Vortec Heads

If I want to do Vortec heads on my 89, 260 HP, 5.7 small block GM with center bolt valve covers what else do I need to make it all happen... and what else SHOULD I do to make it right?
Should I change the cam, do I have to?

No, the flat or roller hyd marine cam is fine.

Do I have to do the intake manifold?

Yes.

Can my Rochester 4 bbl handle the increased air flow?

Yes, and then some. Might have some tuning to optomize.

And can my through the prop exhaust handle the outflow?

Yes