96 5.7 build - cracked block and cracked heads.

flipbro

Master Chief Petty Officer
Joined
Feb 8, 2013
Messages
830
Your 880 casting is vortec block. I have to assume someone has changed the heads at some point. That casting was only used for the vortec 350 with 062 or 991 heads. By the way i have 2 vortec tec blocks and both have the hole machined 4 a mecanical pump. They just had block off plates. aYou really need to follow Bruces addvice and pressure test the block..
 

anesthes

Petty Officer 2nd Class
Joined
May 5, 2003
Messages
186
Marine heads don't get sodium filled valves. If you built them youself maybe. They get the same valves that come on the trucks and other industrial motors. My last build had stainless valves because that is what I paid for.

Remember, the marine motors are a subset of the industrial motors and lag the automotive world by a bit.

Was your 89 motor that had a flat tappet cam a mercruiser or Volvo. Volvo installed their own spec'd cams for a while until their stock was used up.

The '89 was a Mercruiser. Low hour motor destroyed from failing to drain the block. I salvaged the heads, crank, rods, pistons and accessories. Block was toast. Nodular crank, nothing special. It did have "X" rods though.

I've always heard the boat guys say that marine heads had sodium filled valves. But then again, boat guys come up with the most wildest things.
 

NHGuy

Captain
Joined
May 21, 2009
Messages
3,631
If you aren't going to be absolutely bashing this engine the standard valves will do beautifully. The folks who run them hard use inconel exhaust valves. I looked into them, think I found 'em to cost around $80 each :eek:.
My crank isn't forged so I won't be sustaining high rpm, stainless for me. That's what came in my aftermarket heads.
I wouldn't sweat the valve material in your stockish rebuild.
 

flipbro

Master Chief Petty Officer
Joined
Feb 8, 2013
Messages
830
Your 880 casting is vortec block. I have to assume someone has changed the heads at some point. That casting was only used for the vortec 350 with 062 or 991 heads. By the way i have 2 vortec tec blocks and both have the hole machined 4 a mecanical pump. They just had block off plates. aYou really need to follow Bruces addvice and pressure test the block..

Disregard the last part of the post. I had read a post be4 this on and got them mixed up. Theres no pressure testing your block.
 
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