I don't know why my last topic stays on the top list for so long but I feel kinda important. Anyhow does anybody know if all 4-speed Sprint models come with a 3:55 posi Nodular rearend? Please pass the buck. Thanks Dan Zordon316@aol.com

Dan,

the rear gear could be ordered in a number of ways depending on other equipment such as A/C. A 3.55 diffy could be a factory configuration with the 4spd. My base cammer 1bbl 3spd column shift came with a 3.55 diffy. And I'm glad it does, for it helps with getting this 'bird under way.

The proof will be in the PHS docs.

It may be a 3:55 but that is standard 1 brl. does the Sprint get a beefier posi Nodular? Any info would be Great and I am mostly talking about the 1967 Firebird but would be curious about the rest of the 68 and 69 series. Thanks

my 67 came with a 3 spd and 3:08 open gears. going to posi soon though.

could someone explain nodular for me?

nodular would be a higher alloy cast iron center section. stronger form of grey iron to withstand destruction from the drive train due to higher H.P. from the engine!

Nodular iron is a more ductile (less brittle) form of cast iron due to special processing and chemistry control that results in the graphite being in spherical nodules instead of flakes.

My 69' Sprint came with an open 3:55 & 3 speed!

From what I remember, there is a performance axle (3.55 and up non-posi) and a Saf-T-Track. I believe the Nodular were the 3.55 and up Posi units.