New motor has to be torn down

cttandy

Pro Stocker
Mar 9, 2009
1,458
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0
Springfield, Tn
Some may know I traded my way into a 383 stroker. I have $150 in the motor, and it is a fresh build. The history, local kids works in a marine engine shop in Nashville. He builds the motor for his 02 S-10, but the motor won't work with the electronics. The kids gives me $250 cash and the motor to put his s-10 back stock. I paid $400 for the 4.3L so that's where my $150 came from.

He didn't save any of the paper work. All I know past it being a 383 stroker, is it has a .040 over bore and a comp cam 268 of some sort. It definitely has a 400 harmonic balancer, and we pull the pan to verify the 4 bolt main. He said he dyno'd one just like it that made a whisker over 400 HP.

Well, since he couldn't drive his truck, he would start it and rev the crap out of this fresh motor. Now that I got my exhaust on, you can hear a definite lower-end knock. So I am now tearing down the fresh motor. Oh well, I have $150 in it, so I am not hurt at all.

Here comes my question! The heads that are on this engine are off some sort of marine crate 350, or so I was told. They have no markings or identification numbers on them, but they are supposed to have very large valves. Does anyone have any idea what these might be? I would like to know what I have so I can find out what direction I want to go with this motor while I have it apart.

Unless these are some sort of killer heads, I want to get a set of 2.02 double humps from a friend and go with a thump'r series cam something in the 290 range.

I had a set of vortec's that I sold. I am just not sold on a vortec head, and no matter of convincing will change that. I have seen and heard of to many cracking and bend valves lately.
 

LS6 Tommy

MalibuRacing Junkie
May 15, 2004
15,847
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38
North Jersey
Without casting numbers from the heads it's hard to judge, but I'd think any modern marine head is going to outperform/have more potential than the old double humps.

Tommy
 

cttandy

Pro Stocker
Thread starter
Mar 9, 2009
1,458
0
0
Springfield, Tn
They said the crate motor was 1986-era, would you still think the same would hold true about the heads? It is actually the whole crate motor that was torn apart and built into this current form. He said the heads had some work, but wouldn't specify.
 

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