[blown69]

I bought a set of Richmond 4.56 gears for my 69. It's a pro street car with a narrowed 9 inch, 33-21.50 Mickey Thompsons, blown 455, TH400. The car is far from finished but at least it is painted and rolling. I plan on mostly driving it on the street with a some occasional drag strip time. I would like to keep engine RPM down to 5500. I havent chosen a converter yet. The car will have a full interior and most likely weigh 3500 lbs. Just guessing on this since it wieghed around 3600 stock. I am concerned that 4.56s will be a little low for this car. Any suggestions on my gear choice and torque converter choice?

[hal101]

3.55 gears 2500 stall

[blown69]

Hal101 why would you use 3.55 gears? With 33 inch tall tires doesn't a 4.56 gear act or work as a 3.55 gear already? So then what would 3.55s be 2.53 or something like that? Just a thought, wondering what your reason was for choosing a 3.55.

[hal101]

yep sorry i forgot you had 33" tires

3000. rpm should put you at about 61 mph
and that is about as much rpm as i like crusing at

with the tires i hav now 215 70 14 3000. puts me at about 65 mph

those are big tires

[Hard-Timess]

I have several cars with T400 and 4spd trans. Rule of thumb is one step up for the 4spd, IE - 4.11 gears are great for T400 but you need 4.33 for the 4spd. In your case, where you are using 14" rims, suggest you use 3.90 rear gears especially with a 455 and the torque multiplication of the T400. We run 3.90s in one of the cars with a 400cuin engine and the car runs mid 11s at 115 mph with no problem. Enjoy