A question about Compression

Both cars have a big block My car is a 514 with Indy EZ Heads mega block solid roller really wants to run at higher rpm's

Not familiar w/those BIG motors............. But hear less rpm`s are the ticket generally so hard to say. I spin mt 470 past 7000 on most occasions and it`s faster/quicker that way so have you tred shifting higher and did it help? Ask sixpack gut how to get .2+.................

I have not tryed different shift points. The powerglide is new to me and my car. I think my converter is tight but it is loaned to me from another racer. Next race i will have my converter and hope to pickup some.

It is typical with Indy heads to see folks turning less than the combo can do or likes--I mean--I see on the dyno all the time when ports are borderline big or just plain too big to make peak power at a reasonable rpm like 6500--we see combos with dash ones all the time that keep making HP way past 7500-7800 range --that is out of the comfortt zone for most racers and really they should build combos for lower power bands as bracket racers just so it ain't so darn hard on everything--hard to get folks to size the port to the unit correctly and not over cam but that is the way the world is so....
I am saying that lots of guys can turn that big cube engine another 1500--1800 RPM and really see what they got! Too scared to--and rightly so. I hate the myth about big cube loves low ROM yadda yadda--Na--they LOVE to have the crap turned out of them usually to make impressive peak numbers--just like ANY good race engine
Jr Johnson said it best--Give me an engine that never quits going upstairs and let me do the driving. He was right.
The old Shift Loop is long forgotton but PLENTY useful tool --use it to discover what your combo Really likes--Many times just buzzing an engine another 1000 RPM is the key--
Go get him!! Good Luck!

To add to what was said above, compression helps to carry a motor past it's peak. I went from 15:1 compression to 11:1. Heads were unchanged. The cam was slightly smaller. What I noticed is the low compression motor made 50 hp less than high compression (800 -vs- 850) but also fell off much quicker after peak. With the high compression the motor basically flat lined from 6500-7500 rpm. With lower compression it was more like 6400-7000.

What does your car sixty foot? Much easier to pick it up there for the ET gain you are looking for. I would expect you can find the best benefit from leaving the gears 4.56 and getting the correct converter for you application.

Next race i will have my converter in the car. Right now i can beat the big block Chevy for the first 100 ft. After that he takes off. But he runs a 557 gear with a 33 rear tire and a loose converter and he winds his motor up to around 7300. But we have a lot of fun.

I'm not sure about that. I beat him until he changed gears and converter.

The gear will probably make more than enough. Your present 1st gear is probably 1.80 with a 4.56 you total 1st gear is 8.20, if you go to a 5.13 your total 1st gear will be 9.28. I think you will pick up the .06 you are looking for in the 60 ft times.

I picked up over a tenth going from hooker fender well headers to home built big tube's

Are you both running the same mph? Did you give your Mph?