darkside

I've ran a few 6sped cars with 410/s in the past and was thinking about trying 456s , Are 456's still streetable and what would the rpm be at 70mph with factory 26'tires?

rmack

I run 4.56 in my 94 Impala through a t56 with a 27" tire, cruises 2000 rpm in 6th and just over 2900 in 5th...

LS1Formulation

iTrader: (13)

I have 4.30s in my Firebird. Back when it was on the road in it's previous incarnation, I had no issues with streetability. I wish I'd went with 4.56s. Remember, our cars have a .50 overdrive in 6th, which gives you an effective 2.28 gear ratio. The only thing I have to ask is, do you have a stock 7.5" still? Because you'll break those gears really quick if so. The pinion will be so tiny, you'll have hardly any tooth engagement. I have a Strange S60, so I'm not concerned about strength, lol.

darkside

I'm going to order the s60 aswell just need to decide on the 456 gears.

LS1Formulation

iTrader: (13)

Get them, you won't be disappointed.

Homdaddy72

I have them in my m6 ss
best upgrade I've done
Pulls so much better
My wife drives it from time to time and lugs it around.
Why they put 3.23 in a m6 is crazy

JohnnyBs98WS6Rag

iTrader: (1)

GM isn't crazy. Factory rear ratio on all 4th-gen F-bods w/ M6 was 3.42.