I have a 87iroc 305 4brl with a 2.73 rear and swapping a 400sbc. Is that ok for the change or should i upgrade to a 3.73 or 4.11?????

 

Id leave it in until you blow the rear up.
For a daily driver it will save mad gas.
when it does go put in a 3:73, 4:11 is overkill for a street car, no matter what others may say.


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85 Camaro RS 350/350 stealth intake, holley street avenger 670
true dual exhaust. "ButtStang killer"
82 firebird 305 all original - the cat and smog crap."All show No go"

 

If you swap gears you have to change to a 3 series carrier. It depends on what tranny you have and what mods to the 400. If you are running a 700R4 3.73's are even a little overkill because the 700R4 has such a low first gear, 3.42's would be good unless you really have good traction and can come out of the hole real hard then 3.73's would help. Forget the 4.11's those are for cars with 3 speed autos that need more help coming out of the hole.

 

Thank for the info