I am thinking of changing a couple of things and was wondering what you guys think. I have a 73 duster that is just a bracket car, it has a 416 stroker with about 500 HP and TQ. It is a pretty good combination that runs 10.50's and 123(it is down, previous best is 126.5 and and the motor is apart for fresening) It has 9.8 compression and last year I was running 4.56 gears that broke towards the end of the year and didn't bother to change them and I am thinking on changing pistons to 11.5 compression being it is apart. It has a cast crank that I don't want to spin past 7000 rpm, so I was thinking the pistons should pick up some ET and mph so instead of replacing the 4.56's I would try some 4.30's. I figure it might slow my 60's but they are low 1.40's and that dosent bother me. Just wondering what you would suggest and if any of you have been here before. Thanks Craig

You will gain some torq. with the higher compression,so IMO you should be faster overall with less gear,,,,4.30`s

Craig,

You may want to go back to 4:56 or even 4:88.
I have a buddy with a similar combo to yours,
but with 4:30 gears.

His motor is a 408 stroker, Edelbrock aluminum
heads that have been ported, a much bigger carb
than you run, compression similar to the 11.5
you are looking at, similar stall convertor, 904 trans with low gears.
Car is somewhat heavy at around 3400 lbs (67 Cuda FB)but
it's best runs have been 10.98 @ 121 at Vegas
and then 10.92 @ 123 at Fontana CA

IMO the 4.30 gear is one of the best overall 1/8th mile, 1/4 mile gears around.

How tall are your tires?

You probably stand more of a chance breaking the
crank @ 6700 with 11.5:1 than 9.8:1 and 7000.

The tires are 30X9 radial slicks.

Any other's opinion?

Let's see all of your cam specs, converter information and race weight.

Cam is a .600 lift with 268 duration mechanical, car weighs 3165 with me in it and the convertor is a dynamic 9 1/2 with 4200 stall. 1 7/8 headers, 950 hp holley and MSD ign.

4.30 with a better converter and/or compression.

4.56 seems to be working with what you have.

Factory heads.

4.10's on a 28" tire and a stroker seems to be on the fastest smallblock stroker a-bodies around here..
so with 30" id say 4.30 should work well.and keep that converter effecient..fwiw..
cheapst.

S/ST Yes factory smogger heads. A couple of friends have stepped up their combo and I don't want to be left in the dust. I think the 4.30's and 11.5 will work too.

Thanks Guys for all your input.

What were you turning with the 4.56 before

4.56 will help get the car out of the hole...4.88's might mean to much rpm through the 1/4...If you were a 8th mile racer like me, i would suggest 8th mile.

AAR cuda it was a cam motion cam they speced out for my application. If you want specs let me know. fastboy73@aol.com


PBody. I believe it went through at about 7000 before