Need more rpm

Last year the motor turned 7-7100 rpm every night consistantly. This year 6600rpm is all it will do. Had it freshened over the winter and went to a 1-5/8" tube mid legnth header from a 1-3/4". Thats the only thing I changed. Was hoping to get a little more bottom end out of it. Motor seams to be running a little warmer. 220ish
9.0-1 355 sbc, 4412 2bbl. IMCA northern Sportmod, Petronics flame thrower HEI locked advance, 38deg timing. Track is a big 3/8 mile high banked pretty much wide open 99% of the time. Motor sounds good with no hesitation or misses.

Any thoughts or suggestions?

Thanks!!!!!

Did you check the valve springs?

Heads were gone through with brand new valves and 941-16 comp springs this winter. Same as what I had last year.

thanks!!!

maybe the coil is giving up or the gear on the distributor is off just one tooth. we had this problem last year. car ran like a champ all the way to about 5900 rpm then would level off....like we were up against the chip. after we took the dristibutor out and put it back in on tooth over. we found an additional 300rpm to get us to our 6200 chip.

also if the carb sat over winter you might want to double check and make sure its running good. i like to go ahead and run through it to make sure its not sticking a float or the mixture screws havent moved from when we took the carb off or putting it back on....

EDIT: also might want to check the lash on the valves. might need to tighten or loosen them now that you have ran the motor

I have another module I can throw at it. The retarded timing crossed my mind when it was running warm. Could it be retarding at higher RPM's with at load on it? I have it set a 38deg right now. I'll check my valves this week and battery leads. The motor ran really smooth, just not fast. I was thinking that maybe the tach was off but when it got to around 7000rpm in the past it really singings a pretty tune. Didn't hear that last weekend. It was opening night and got spanked by the 4bbl crate motors.

Thanks!!!!

If the only thing was changed is the headers, put the old one's back on.

Just a thought, is there something diff suspension wise from last year that the car is just "hooked up", or maybe even tight therefore not carrying speed through & off corner ? Being "hooked up" & now lugging eng will add heat, now maybe time for a gear change if this is the case. Always run a ground wire from battery to stud\bolt for distibuter hold down.

p.s. The MSD HEI are rather expensive but very high quality !!

Since the engine was freshened I see lots of things that could do what your speaking of. Valve job crap, ring seal, intake gaskets misaligned those type things. 2 barrel engines are very picky. It could be the header but if it lays against the pump all the time likely not. I would be looking more in the ignition department.

the cam could have been installed on the wrong intake centerline when it was freshened

I changed Modules and free'd the car up a little. Plugs looked good. We'll see what happens tomorrow night. Thanks for all of your help!!

I was thinking about the gearing as well. Did someone switch gear perhaps, and this was overlooked?

Good luck, let us know how it ran.

k