Gears
 

Wondering if I made the right choice picking 3.25 gears for my combo. Engine is a 461 with e heads ported to flow around 300 cfm performer rpm intake comp cam hr288xr roller cam with a th400 with a continental 10 inch 3000 stall and a kens speed and custom d1sc procharger.

Plenty of gear for a supercharged 461, you could have easily gone taller (lower numerically).

You made a good choice.

I've got a set of 3.70 for my 9 inch but was thinking it was to much. When I had 8.2 with 3.55 I don't remember the car being much fun at 75 lol

I am finding that after talking with some of the Pontiac guys in the know, that most of the time the big gear thought [3.55-3.90-4.10] are not needed with todays technology.
I have 3.90's in my car now and have been told with my combo [Stump Puller cam] I can do with a set of 3.23/3.36 gears, don't need the tall ones any more.

Lower numerical gears (2.56, 3.08, 3.23) = tall gears. Tall gears are highway gears.

Higher numerical gears (3.90, 4.10, 4.56) = short gears. Short gears are for drag racing and such.

Pontiacs generally like taller gears than the typical Chevy might use for maximum acceleration, because of their superior mid-range torque characteristics.

You can have a very quick Pontiac 455 street car with 3.08 gears. No need to gear it down to 3.90 or 4.11 like you would a 327 Chevy.

you for got 3.55

That gear ratio with the charger on top will be the best of both worlds!

Not the best highway gear but great for city driving and drag strip performance. Your only problem will be getting enough tire in there to hook that thing up when you put the hammer down.

I had 2:41's and changed to 3:42's. I made the mistake of changing gears before I was done getting my engine (a complete rebuild) completely tuned. I ended up changing to E-heads via Kauffman and I'm making so much power now that I could easily handle a taller gear. I wish that I had gone with 3.08's. As it is, I'm looking for an overdrive transmission and completely avoiding highway driving. It's great around town and my commute to work doesn't have anything more than 5 miles above 55mph speed limit. On the highway, it's just pulling to many RPMs to think about a trip much over 100 miles.

390s here running out of steam putting 342s back in then back to tnt

I went with 3.73's behind my 462/Th400 combo. Revs are high for highway use, but I can cruise around town at 35-50 mph comfortably in 3rd and have all the power I need to zoom around things without needing a downshift.

gear choice is dependent on how YOU use your car....not someone else.....only one way to find out what you like..

Roger That! I like to cruise along at 80MPH and slam the go peddle down to wave bye bye to the other guy so Low gears would not work for me!

I agree...I drive 100 miles to the track..my 3.08's are great,went to a cruise night last weekend,stopped for a coffee out on the cruise,caught up to the pack ten miles down the road..had to speed slightly to catch up!

It's gonna be mostly street use track from time to time. Just wanna be able to enjoy it.

I have had 2:56, 3:23, 3:42, 3:73 in various Pontiacs. 3:23 was my favorite.

I have a 3:08 rear that I would like to install in my firebird that I would like to try.

I really like the 3.23s in my Formula even with a smaller engine than most of you guys are running (440 ci). Plenty of punch around town and a pleasure on the freeway and mid 12s at the track.

time runs
 

FWIW had my car out with 390s best 11 16@118
Put 342s back in went [email protected] at Norwalk

Lost a tick on 60 1.50 to 1.52

Love my 3.15s , they pull like 3.73s in my other cars.