69 cutlass S 350 tranny swap
#1
69 cutlass S 350 tranny swap
I've got a 1969 Cutlass S convertible. It has the original 350 Rocket and the 350 turbo transmission. Did the 1969 year model come with a 4spd manual transmission option? If so, which transmission was it? If I can ever come up with the money to switch from my 350 turbo to a 4spd I'd love to know my options.
Thank you
Thank you
#2
Yes, the Muncie four speed was a factory option. Two things to consider. First, Olds typically did not drill the crankshaft for a pilot bearing if the engine came from the factory with an automatic. This isn't really something you can correct with the engine in the car. Yes, there are aftermarket adapter bushings that don't require drilling the crank but you then need to trim the input shaft instead. Reviews of these have been mixed. The other issue is the rear axle ratio. While your car may have been ordered with any of the optionally available ratios, standard equipment with the TH350 would have been 2.56 gears with the 2bbl motor or 2.78 with the 4bbl motor. Neither of those ratios was even offered with the four speed; 3.08 was standard. Excessive clutch slipping with the manual trans and low-numerical gears can suck the fun right out of a manual trans.
#3
Changing out the rear diff gears and adding posi-trac was gonna be my first upgrade. Once I get that done I'm gonna explore the 4spd transmission more in depth. I figured I'd start looking around for a 4spd transmission now, maybe find a good deal somewhere.
#4
The Munchie are strong and desirable, so not cheap. I am collecting the parts this year to do a 3.08 posi, already have them, just need the bearings and seals, another $350. It is big dollars for anything in a pre 71 Type O 8.5" rear, only 3.42 and 3.90 gears available new. A 3.08 with a 4 spd won't add any extra highway rpm vs say a 2.78 due to an actual 1 to 1 ratio. No 200 to 300 rpm torque converter slippage like an automatic. I am gathering the parts for a TKX 5 spd swap. The trans is double the cost but isn't 50 years old.
#6
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