[6t8bird]

Alright guys....so i am rebuilding a 68. It has saginaw 4 speed in it right now but i dont know how they are. i have only driven a munice 4 speed. From what i see the muncie is a lot better but if the saginaw can handle the power the 400 will be putting out, it would be a lot easier and cheaper for me to rebuild this one rather than buy a muncie. Will the saginaw be able to hold its own against the 400? Thanks

[Jack Gifford]

I remember your question being discussed on one of the PY forums (try searching for 'Saginaw'). I could be remembering wrong, but it seems to me it came down to "how do you drive?" and "how sticky are your rear tires?".

[drew1967]

if your going to drop the hammer down on the sag....NO! the sag was put into small block chevy's. not hi torque engines. mostly a taxi trans! the muncie im told is also just as weak when it comes to a pontiacs torque. although i havent confirmed this i will soon! i plan on either winning the race or grenading the damn thing trying! my combo is a 455 ho with 4 spd muncie and a 4:11 posi rear end. well see if things hold together!!

[6t8bird]

thanks guys. from what i read it seems like the m-20 muncie would be the best for 3.73 with posi. I figured that would be the way to go. i dont plan on drag racing but i know i am gonna have to smash it every once awhile and i wouldnt want my tranny to explode.

[67FB400-4SPD]

I have a friend with a 69 GTO that we dropped a built 455 into with 3:55 posi rear and he runs the Saginaw with no problems and we have beat the daylights out of that thing for years. I am also putting a 455 in my firebird with original 4 speed muncie from his GTO that I rebuilt this past winter and I intend on running 3:73 posi. I would say both trannies have their advantages but Saginaw would take the flag because it does not have Aluminum ears to bust off when beat to death. Just my opinion!! Like he said above...it's how you intend to drive it.

[6t8bird]

i am not doubting your experiences with the saginaw but does anyone else have anything to say like that about it? If thats the case i would just rebuild mine......im not going to smash on it all of the time but i would like to be able to down shift into third while im going on the freeway without having to worry about my tranny blowing up. what do you guys think?

[Jack Gifford]

Did you search these forums for old discussions of the Saginaw?

[6t8bird]

yeah...ive searched the forum and everything that i have seen tells me that a muncie would be better, but i have been talking to people and they said that unless i am speed shifting i dont have to worry about the saginaw. They told me the synchronizing of the gears is what makes a muncie good...so as long as i make sure it is in gear before i pop the clutch it should be better than the muncie because it doesnt have aluminum gears. Saginaws are used in trucks and they can handle that so i dont see why they shouldnt be used in this application. That is why i was asking if anyone else had anything positive to say about it.

[Cammer-6]

I dont know of any transmission with aluminum gears,except RC cars.
I think you meant aluminum case???
Torque ratings tell the truth about the strenght of a tranny. Saggy is about 1/3 lower.

[Colin_McF]

I am in the same position as you 6t8bird as i have a 68 Firebird with a small block chev and a Sag 4 speed thats being replaced with a 68 400 and i will stay with the Saginaw for now.I have done alot of reading and asking questions as as said above its all in the driving habits. I ask a tranny builder who sells both Saginaw and Muncie trans and here are his reply's.

"Hi Colin,
is your motor stock? and how do you intend to drive the car? it is
possible that the trans would live behind your 400 but I would
recommend going with somthing stonger like a super t10 or a
muncie., also waht rear end gear are you running?
thanks, Bob"

This is Bobs reply on me using a Saginaw
"Hi Colin,
I would say it would probably live behind your 400, the 3:11
saginaw is rated somewhere around 300 ft lbs of torque. I would
not recommend launching the car hard out of first. we will not
warranty against broken teeth. we will guarentee the trans will
work as intended.
thanks, Bob"

So basically I am sticking with the Saginaw until i blow it or if it lives thats great.


good luck with the switch I am a couple of weeks away just gotta finished the wifes 69 FB.

Colin