90Mustangfan

yea go with 4.30's or 4.56, Id like to say with the power run 4.56 if its a trailer queen, but if you drive it to the track or drive it now and then run 4.30's, its hard to tell likley 4.56 are a extremely steep gear, so if you had slick you could run a 10.5 and launch hard off the limiter or a 6k launch, youll cut some low ets with 4.56's overall its up to you

Grimace5.0

You can't just pick a gear to run...unless you like to do gear swaps and have extra $$ floating around.

Guys, there is more to it.
What gear is in the car now?
What RPM does it go thru the trap at?
What RPM does YOUR engine start to drop off at?
What heigh are the tires?

88BlueGT

^^ +1 You really need to have everything matched up. But 4.30's really arent that bad.... I know two people w/ 4.30's and drive them as their DD's. Yes, the mileage would suck pretty bad but its for 1/4 mile anyway. As long as it works with your combination than go for it.

rsw007

leave the 3.73's and spray it with a 150shot.

Gtdaniel

the car goes through the traps about 4600 rpms.

The gears I have now are 3.73
then the combo that I going to put together,Ohh also forgot to mentions that its allready blueprinted and balenced its a 306. my local engine builder said the cam and my set up will be good to 6800 rpms..
I will be running a slick,probaly a 28 inch tall tire, hopefully it dont hit the fender,


also I was thinking of going with spray but want to try all engine first the go spray

Gtdaniel

And I do like doing gear swaps.

I get gears from my cousins out in Pheonix AZ,they own a shop out there call AZ defferential specialist.I worked the for a summer two years ago.I can get the gears for $50 buck shipped.

ikeybmg

i wouldnt go lower than 4:10 in a 1/4 mile car. 4:30 or 4:56 would be great for an 1/8th car but having to hit 5th before you get thru the 1/4 sucks IMO.

tinman

If you are racing over in Alber. You have altitude/thin air to deal with.
When that is the case, run more gear than you think you are going to need.
Game here is to get the car into high gear asap.
Get around some peeps running stock eliminator and ask them what gears they use there and at Denver etc.
BTW, is Valley Racing still operating over there? If so, ask them. I've known those guys for years. Even though they are (were) a MOPAR shop, they are good folks.......

Gtdaniel

I think so.will ask them.

J 85 GT

i have an 85 with 4.30 gears. my car has a comp cam, milled p heads, rpm/airgap with a race carb etc. so the gears work out well with the rpms and only a 26' DR.

but unless the car is pushing 6grand + get 4.10's.

when i first started building the car and did the 8.8 in it i still had the stock motor in it for fitment ****, and the gear was way to much for the car. i had 1320 marked off down on a back road by the house, and i was running wayyy out of gear in 4th and that car fell off right around 5200 which is where im sure you'rs will as well. it would be taching out wayyyy before the quarter.

trailer car or not, its a matter of where the car will be quikest, local off the stop light runs or 1/8th mile it would be good. but for the 1/4 mile no way.