Questions:

By falling off, do you mean it just does not pull as hard, or it take a really long time to pull up rpms above 4k? Not pulling as hard above peak torque is very normal, but stalling out is not.

What intake are you running, single or dual plane and what is the rpm band of it rated for?

What lifters are you running? Hydraulic lifters and matching valve springs will tail off in the 5500-6000 range.

What AFR do you have at WOT? 12.5:1 is where you want to be for optimum power production at WOT.

I have not driven you car, so I do not know what you are feeling. Remember though, that a short stroke engine is designed for high rpm use, not torquey power. The beauty/downfall of a 289/302 that is build with forged bottom end solid lifters, and high rise intake is it will spin up and howl like a banchee, but will suck eggs off the line. It could be you are miss matching parts or you could be looking for/expecting torque that you will not have with a short stroke engine. Then again, something could be wrong, but I think you are expecting the

 

iirc, he's running a roller 5.0 motor now. Right? If so, torque shouldn't be an issue.

Off the wall idea: what if the fuel curve is leaning out at high rpm's? I had that problem when I swapped a set of Trick Flow heads on my car. The secondaries were running so lean that the motor fell on its face at 5500. Upjetted the secondaries and now it flies to 6k and keeps going

 

thanks urban and Tad,

i would love to get a video (in car while flooring it through 1st, 2nd and 3rd), but that thing is broken :-(
it's a 72 or 73 non-roller, edelbrock rpm heads, cam and intake (dual plane). at least all according to the seller. I can only verify the heads and intake.
said they're the 2.02 intake version, but I haven't verified that either. might pull a cover so see if I can find identification.

I'll definetly check again on timing (will open a new thread with curve numbers and AFR and plug pictures)...
i'll aim for 12.5 at WOT and post the A/f curve at wot in relation to rpm.
gives me somethingto do on the weekend :-) keeps me out of the pub ... *g*

 

Out of the pub? That's no good. Wish I had a pub to go to...

 

The intake and heads are pretty good, IMO, if that is what you have. The cam is...ok. The duration should give you a power band of 1500-5500. It is a flat hydraulic, so valve float could be an issue. Valve lift is good though.

I ran some close comparable numbers using AFR heads and Comp Cam that I had on file. The peak torque would hit around 4k at around 375ft*lbs at the flywheel. Horsepower would be about 360-370hp @ 6000. At say 6k, the torque numbers drop by 30-40% from peak, so you will feel it flatten out some.

Assuming 25-30% power loss through the drive train, that puts this motor at 250hp at the rear wheels.

Oh, and in Texas, the garage is often our pub .

 

One item I don't see information on is what Cam are you running, or at least what lift and duration are you running? Cams a lot of times are ground to give peak power in different parts of the RPM range (Low/mid/or high). The really wild ones make no power down low but "kick" in at the higher end (really lopey almost die at idle types).

What you're feeling could be nothing more than the type of cam you haev installed. Designed for midrange power.

 

.....

 

will do that. CPR suggested that once in the past as well.
Will get a long vacuum hose and a buddy to watch the gauge. probably just gonna tape it to the window. I have a imperial gauge as metric is useless if I have to talk to all of you in the forums *g*

 

My car has Edelbrock RPM heads, performer intake, and 650 AVS carb. The cam is matched to the heads as well. I can not remember the duration. I have the paperwork somewhere. What cam do you have?

Mine is said to be a 350 hp engine as well.

 

if your still running that 570 i'd be willing to bet its your bottleneck. it was great for your old 289 but with what you have now you need something bigger.