Ok so I am almost done with this 455 swap...kinda lol. I dropped the engine in but the driveshaft seems to long. Found out that I need a new yoke for a th400 transmission. I had the st300 transmission. I have a 68 Skylark. Has anyone done this conversion? did you have to get your driveshaft cut or just get a new yoke. If so what is the correct yoke and where can I grab one. I have a short shaft th400
You will need to shorten the shaft around 4in or so Slide yoke trans with 1in to 1.5in of yoke stem visible, then with suspension loaded measure from the center of the the yoke where the u joint cap sits and that will be your measurement
I believe the driveshaft should be somewhere around 55" from u-joint center to u joint center. You will need a 400 yoke, I believe a short one. Sumitt sells yokes, https://www.summitracing.com/search...4+4294949291+4294945435+4294949231+4294843590
Found a place out in Merrick Long Island that can cut the shaft for $80 and they also sell the th400 yokes in several legnths for $75. I will take that as a win. It's called Nassau driveshaft
Check the drive shaft that was in the car with the 350. it probably is a 2 piece, then you need a new stronger shaft anyway.
No, actually all 350 Buick A bodies used a 2 piece drive shaft, look at the end near the universal you'll see what I mean.
Are you sure? The drive shaft from my '72 Skylark custom 350 convertible had a one piece drive shaft. That drive shaft is in a '99 2 wheel drive Jeep Cherokee now that was suppose to be the test drive shaft! LOL To this day the engine in that beast has busted 4 power glide transmissions, 3 TH350 transmissions and 3 Ford 31 spline 9" rear ends! We figured the drive shaft would be the weak link and the first thing to break, go figure.
