I've got an '89 formula 305 tpi i have full exhuast, lt1 cam and every other little bolt ons. my fastest time with 2.73's is 9.4 sec. in 1/8 mile and a 2.02 60 ft. i just got 3.73's havent got them in yet but just wondering what my time would be in an 1/8 mile. THANX

 

your gonna love the new gears, i just made the same swap and the difference in them is unreal. the 3.73 gears will make it feel like a new animal. it complements my mods perfectly........

 

don't be surprised if it knocks a full second, or even more, off the 1/8 mile time.

 

Well, if you really plan to max your ET you should plant a set of 27" slicks out back to get that thing hooked. Running 3.73 leaves you out of breath with a TPI at the traps. A 27" tire will hedge that risk and keep you in your powerband for the full run. Street tires are also gonna want to spin spin spin.

 

Won't happen with just a gear set change. I will say he'll still be in the 9's (1/8 mile). The reason is that the low gears will spin him right through his usable rpm range. In theory you should cross the 1/4 mile traps just over your peak HP rpm.

For his 305 even with a full exhaust and cam I wouldn't go over 3.23's or max 3.42's unless something is done with the stock heads and intake.

 

I am putting the 3.42 in my 9-bolt. Should be in the car and have everything running by May. The 3.42s are what everyone on this board, mechanic friends and comp cams said would be best to run. Of course that is for my 305(it will actually be 335). Other people run them and love'em.

 

3.42 's in a 9 bolt rear

impossible , you mean 3.45 's

 

My bad.