I have got my boat running really well EXCEPT......... I run about 48-50 but the last 1/4 of the throttle is unused and when I get into that last of the throttle it cuts out and pops or rattles.
Someone said that I should check my powervalve in my Holley? Any other thoughts? I am running a BBC with an aftermarket aluminum intake and a Holley 3310. Can the powervalve only yeffect me at the high end and run well the rest of the time?

so that would require a new secondary vacuum setup?

I have read your other post. You said you played with the timing. What is the total advance at 3000RPM. A mild BBC should have about 34 to 36 degrees total. Also some of the HEI's have different advance curves, older 80's era camaros and vettes had a more aggressive advance build into them. You might have too much advance. When you say it cuts and popps does it actually stall the engine.
I had way too much base timing set in my MSD and it sounded like a misfire when total advance was all in and popped too.
  T.J.

You will need a timing light to check the advance.  I would set it 10-12 degrees at idle and then check it again at 3000 RPM's  at this engine speed all of the advance should have been applied by you distributor.  If you don't own a timing light you can get one for under $50 I am sure.  I set mine by ear and then out in the water under load, but you cant really tell at what points the dist is advancing the timing curve by ear   My numbers always match up with those posted when I do use the light though

Thats very true.  I had a buddy with one and we made marks for 30- 35 degrees   so I could still use my cheap strobe style

I know it won't be any help for you Austin but I'll have my timing light at Parker if anyone needs it.

your the man I need to see there mine took a dump.

I will check out everything you guys have suggested. I have two tanks that draw at the same time so I woudl bet against the clogged line unless it is aftre where they meet. But a weak pump is possible except that I have two electric ones that I even turned on during the problem to see if that woudl help and it had no effect. I am back down to timing so i guess its time to put the light on her.