Everything seems to be holding strong on drive. Oil is changed often and always a nice clean blue. I have gone back and forth with a edlebrock performer duel plance and the single plane. Have not noticed any difference on that. But maybe once I dial in the timing it will come into play. I will verify the 34 TA on the timing.

Thank you.

What are you using for exhaust? Have you done a compression test what are your numbers if you have?

What heads are they ? I don't know of any GM Performance 200cc heads. The Large Vortecs maybe ?

Which Comp marine cam ? Your lift doesn't lead me to one.

That intake is doing you no favors as Ryan pointed out.

Most Goodwrench motors have crap for compression with 76cc heads. What is your Compression ? Edit: just re-read and see you mentioned 64cc, Please double check and provide us with the cyl heads Part#. Reason for asking, a low compression like 8:1 won't like much of a camshaft.

As far as my call right now, sorry if this hurts but I am still here to help, going by your innacurate listing of parts (I haven't mentioned the impossible 1.90 exhaust valve yet - ooops, just did) and possibly poor choosing of parts, that you may have outdone yourself by buying first and asking later vs asking first and buying later.

Let's see what accurate info you can give us and what we may be able to do to help.

There are a good amt of small block guys here with a lot of hands on experience, so you picked a good place to ask.

Running Merc stock exhaust manifolds with wide open thru hull. Compression test is consistent across all 8 cylinders. Thinking they were at 140ish. Motor has 212 hours on the bottom end.

Understood. Can get the actual part number once I get home. At work right now. And any info is good info. You won't hurt my feelings.

I think SBI nailed it on the compression . Those numbers are way low.

Found it in my email.

Cam: 249-XM-CL12-240-4 Jegs part number.

Heads: Sorry, they are 210cc runner, 64cc, 2.02 intake and 1.60 exhaust. Brand is pro-comp performance.

Compression was 160ish. Sorry for the bad info guys. Did not realize how involved this would get.

I think your combination is killing it. The cam is really too big for those heads on that displacement of motor. The intake velocity is no low making for a sluggish motor. Slap those heads on my 413 and the intake velocity would recover, but not be as good as my AFR 210. A smaller cam maybe the 212/218 or 218/224 max would have been a better choice on those heads. A standard performer with no plenum notch and barrels isolated between the left and right side of the manifold would make for much better response. Cranking compression sounds right for that cam and those heads. Probably around 9:1 with the 64cc chambers. Just my 2c. Good luck. Oh yeah, bump the timing, that will help your part throttle response as well. Also verify TDC is 0 on your balancer. I've had it where my old motor hit a weird wall and I then realized it was the ring on the balancer slipping. No pinging and no hard starting on mine, I happened to find it after I pulled the motor for something else and saw the rubber shifted.

Thanks guys, going to go after the timing number one. And then swap out the manifold after I play with timing back to the dual plane. The motor does run strong the way it is. I just think it should run better. Feel like I should be able to crank up to at least 5500RPM. My first attempt at going faster on the water. I am seeing it takes close to perfection and more planning before getting a bunch of parts and slapping it together. I did read a post that every mph on the water is earned by pure HP. I am a believer in that!!!