Hi Guys,
With all the mods I've done on my car (see sig), it seems to stop pulling hard once it hits about 4800rpm. It will then go up to about 5200rpm (barely) before it completely falls flat.

I know the XFI cam I'm running is suppose to have some crazy ramp-rates, so I was wondering valve float would cause this problem? The springs I'm running came with my Dart heads and are suppose to be double-springs that support up to .600" lift. I'm not sure who makes the springs.

Any thoughts on this?

Thanks!

 

Start with some 30# injectors. I'm pretty sure you're running out of fuel. It's called lean misfire. I don't like your combination of springs and rockers, but even so, only fuel explains your symptoms. Unless you're using a dizzy from an '87-up pickup truck. Those have built-in, non-adjustable rev limiters set for 5250 rpm. If you have one, sell it and find an F-car version. I had my '91 LO3 to 6200 (accidentally), so I know they're not limited.

 

Thanks for the reply Atilla! I replaced my distributor with one from Autozone a year or so ago. I told them I needed one for my specific car but who knows what they gave me. Is there a way to tell which dizzy i'm using?

 

put it in neutral and give it about 3/4 throttle, briefly. If it absolutely will not zip to 5500, even for a millisecond, then it must be the truck version. You should be making power well past 5500. And with no load, even 24 pounders should get you past 5500.

 

I tried to rev it in neutral and it did rev to 5500rpm. Guess it needs the bigger injectors?

 

I really do believe so.