83ttopgt

Got an auto in my 88 gt (c6) so no overdrive. Was told car has 4.10's in it now. Seems more like 4.56's according to the wallace racing RPM Vs. Gear ratio/tire size calculator. Either way its too much gear. I am gonna pull the cover this week if time permits and see whats actually in there.

I am looking at something in the 3.27 or 3.55 range with either a 255-40-17 (on it now) or maybe upgrade to a 275-40-17.

Car see's a bunch of varied driving, no drag strips though, a fair bit of highway, but mostly cruise nights in the 50-60 mph range.

right now around 50 ish (speedo is off, guessing by traffic flow) its taching 3000-3500.

Stall speed on the converter is around 2 grand. I know the cruising speed needs to be above stall or it will create a ton of heat and kill the trans, but how far above stall is "enough"?

Thanks guys

mjr46

with no overdrive and no track racing 3.55 would be decent for intended use

83ttopgt

Thanks. It MAY see the track once a year at the tasca mustang thing, but mostly for fun.

Its a cruiser right now. Besides its got a 460 based 545 stroker, it will pull a taller gear.....

I already have a set of 3.55's from another project, so I'll try them first and see how it goes

nitrous_bob

Don't pull the cover.....just do the spin and count. 1 revolution on the tire to how many times the DS spins

3500 1:1 could be 4.10

.68:1 tachs about 2500 doing close to 70

83ttopgt

I'll probably still pull the cover, I get a slight growl sometimes. I wanna check the pattern etc. I didn't put the gears in, so I wanna check em.