It's refreshing to see someone who believes in the THM-400 transmission. Everybody is slap-happy over the 4L80E. You can bulletproof a 400 and it will last. You can bulletproof a 4L80E and hope the valve body separater plate or the forward clutch doesn't fail.
Did the 400 4x4 trans come with 27 splines?? I found one and the guy said it has 27 splines and that it came out of 80's chevy truck. I have searched online and it says all 400s came with 32 splines and the ones with 27 are the THM375 the lesser of the 3 turbo 400s. the next was the 475 with straight cut gears. What do you think? Thank you, B
I'm not an expert on all the variations. I do know most common are 27 and 32 spline. Unfortunately I no longer have them separated to look. Maybe this will help. www.offroaddesign.com/tech/offroad-design-transmission-knowledge/offroad-design-th400-technical-information
