Talk to JC Performance he just dynoed my first engine yesterday & made 450 hp & 440 tq I used the edlebrock alum heads & kept the fuel injection. Sorry for the camera phone pic

Being that I am still on the Alpha drive, I need to be careful how much power I make with this thing. I think if I stay under the 330 horsepower mark it should live fine.

I thought somebody made a drop in valve spring for the vortec heads that increase retainer to guide clearance to .500 lift, but I can't seem to find it. I will need to do something to run the comp roller cam I am looking at.

Crane made spring set. If memory serves it was p/n 10309. Don't know if you can get it now.

I thought somebody made a drop in valve spring for the vortec heads that increase retainer to guide clearance to .500 lift, but I can't seem to find it. I will need to do something to run the comp roller cam I am looking at.[/QUOTE]

I am going to be pulling the motor apart in the next couple of weeks as the weather permits, still melting snow up here in NH.

It will be stock 1993 350 bottom end, vortec heads, dual plane intake, holley 600CFM DP carb, silent choice exhaust with no mufflers in the 4" tips, and whatever cam I choose from the two below.

I still have a couple of detail questions left to answer. First, should I run a comp XM-264-HR or a comp XM-270-HR? The 270 might soften the torque hit a bit on the alpha, but needs to rev a bit higher, around 5200 to make peak power. Will this be alright on a stock bottom end? Also, will reversion be an issue on the stock exhaust with the 270? Will I have any trouble idling down enough to not kill the Alpha when shifting? Will the torque I give up going with the larger cam really hurt the boat coming out of the hole? I will freely admit to secretly wanting the bigger cam for a little lope in the idle.

Does anybody know what the compressed thickness is for the Felpro headgasket used in the 17232 kit? I can't seem to find that information anywhere.

I am curious what I can estimate for horsepower, I am thinking 340-350.

I am also looking for some initial jetting to run on the holley 600 DP carb. Something to get me close, maybe a bit on the rich side to start. I am thinking probably 30-32 degrees total timing to start with.

Any input is always appreciated.

I pulled the motor down this weekend. Much to my surprise, it is a factory roller cam currently installed. The pistons are pretty much a flat top with 4 valve reliefs. I say pretty much because there is a very minor dish to them, I will post a picture up where you can sort of see the piston design. . The tear down went well, and there is a ton of room to work in that boat after removing a couple of panels. Now for hours of cleaning, and waiting for parts from UPS, and the rebuild will begin. Pardon the bluish tinge from the picture, I am working under the tarp tent that keeps the boat enclosed in the winter.

Before starting:


After this weekend:

Pistons should be perfect with the Vortec heads. Right at 9.4:1 compression using the .028" gm gaskets. You may need a different ignition module because the Vortec engine runs less timing than your old engine. Keep total advance around 30.

My motor has a 24s module. I am pretty sure that runs 24 degrees advance. Can I run 6 degrees base timing instead of 8 to get my 30 total or will there be a problem running the lower timing at an idle?

As long as the idle is OK, set total and it will work fine. It would start and idle better with around 10 initial, but try it and see how it does. Be sure and set total, those advance stampings are not always accurate.

Bob
Full Throttle Marine

What would your suggestion for a module be? Either a 20R or V8-HP would allow me to run 10 base and 30 total, but the curves are totally different.

Also, I am still not sure what I should jet the 600 double pumper with to start. Any suggestions would be good, as the motor is in the boat and will not be going on a dyno anytime soon.

whyle the heads are off if you have or borrow a degree wheel and find tdc and mark the bllancer or timing mark to make sure you have the correct timeing..then degree the cam..