Take a guess where the bottle neck is!

1972DusterPaul said

I have a similar set-up with my 340, it runs out on top end also, but I currently have an Edelbrock 750 verses your 625 Barry Grant. I only bought my car this summer, so I have no idea on the times it would run.

You make no mention of your exhaust system, mine has stock manifolds (of unknown vintage) and a stock dual exhaust system other than Flowmaster mufflers.

I am switching to an Edbrock Performer PRM intake (the price was right otherwise I would have gone with the Air Gap). I have headers coming and plan on redoing the exhaust pipes also this winter.

And as the cam goes, mine is similar to yours...I am swapping in a Comp Cams "274" when I paint my engine bay.

I would beef up your fuel lines to 3/8" and double check your fuel pump is working properly.

And I would say you need more gear in the rear...I have a 3.91 in mine...that should wake things up a bit.

My 2 cents,
Paul

Click to expand...

I have long tubes on it, and a full 2.5" system with a pair of chambered mufflers. I had 4.10's in it when I first set it up and it was really alive even with the 28" tires I had on it. Since I went to the 3.23's it just lost all its guts. I'm working up a plan to wake it back up again. I want to ditch the cheap highway tires and put a pair of 26" drag radials in the back, I also want to pull the 727 and put my old 904 back in it, the 904 is lighter, fits better, and always shifted good. Just the front seal was bad on it, so it leaked from the front pump a lot (it could be the pump leaking for all I know, I don't know much about transmissions). I'd also like to pull the SG/3.23's and put my 4.10's with the Detroit locker back in it. Then install that Airgap I have to finish it off. I think, if the engine can work with that converter in the 904 (its an old factory 360 converter) and I can get traction I wager I can pick up a second or better in the 1/4.