Hey guys, i was just wondering which gears to go with in my 1978 Firebird, the car has a chevy 350 bored 40 over it has some kind of aftermarket piston not positive what kind, comp cams extreme energy 274, edelbrock perfomer rpm heads 70cc, edelbrock perfomer rpm air gap intake, edelbrock 750 cfm, msd digital 6 ingiton box, msd pro billet distrubtor, flowmaster exhaust, turbo 350 transmission thanks

 

Hey, do you have a stall converter in your car? We've got the XE284 cam (next step up from the XE274) and it doesn't start making power 'til around ~2500 rpm, so I imagine the XE274 is probably similar in its characteristics. It would probably like a 2500 - 3000 stall. Also, how do you intend to use the car (or where)?? If you're mostly street, then 3.42's are a nice gear with an auto (we've currently got them in my Dad's '73 with a 4-speed). However, if you want a street/strip, or mostly strip car, then go either 3.73's or even 4.10's (although 4.10's will SCREAM on any cruising 60+ mph!!). I had 3.42's in my '81, and they were nice.

 

I have a hughes 2800 stall, what should my car run in a quater mile.

 

Well, depending on how well your engine is tuned, and as long as you can get good traction (running DR's or ET Streets), I'd say probably mid-low 13's, and maybe even a high 12 if all the conditions were perfect. I can say this with a reasonable amount of certainty, comparing your engine to the 350 in our '73, and also knowing how a friend of our's ran in his '78 Z28 with a motor that's built almost identical to yours, except a 4-speed, and he ran 13.1 down the 1/4 mile.

Like I said above, if you want to run the best in the 1/4, but still be "somewhat" streetable, then 4.10's are going to give you the best acceleration . 3.73's would be a little less extreme, not quite as quick in the 1/4, but a little more street friendly though.