It totally SUCKS!!!!!! I had an M 21 stock unit in it and decided to replace the motor and trans as a unit since the clutch was a 10 spline and it was brand new... Now I wish I would have just bought a new 26 spline clutch and used the M 21. I should have sold the M 20. Damn, it pulls like a freight train in 1st and 2nd then falls on its ass in 3rd and 4th. The car has 3.42's and weighs 4020 lbs..The car seems to run well but after 2nd gear, it loses pulling power, Its not the motor.That 350 has a 118 cam,headers and 2 1/2 exhaust . It seems to just hit the power band and wont pull anymore...
Fuel delivery issues i bet! clean out the gas tanks, blow out the lines, use a new filter and you'll be fine. also use a new fuel pump.
Sorry to hear that, Pat. I just stumbled across your post by accident. Why the hell would I be looking in this forum ?o No: You know , that whole TH400 thing I've got in my car.:boring: I'm jealous of you lucky ones.:3gears: At least my top goes down.:laugh: Good luck with your new problem.:TU:
Thanks Kevin...I know its not fuel... New pump, lines all cleaned,new vaccuum lines tank has a new refill of 93 octane gas..I believe its the transmission. I drove this car home fresh out of the barn(10 years) with older gas and it pulled alot better than with the M 20. I am thinking they used the M21 to match the weight and gearing of this car. I have a notion to swap a 455 and the M21 back in and whoop the butt off this car. Its been fighting me every step of the way back to driveability..
Adam, Thats what I was hoping for as well.It seems to run fine and has absolutely no stuttering,missing or anything. It just seems to stop pulling like the first 2 gears. This was the first trip out(less hood as well...lol) but I have been messing with the timing as well. I am hoping its in the timing and nothing serious. I have good oil pressure and its not overheating. I may go and get a new set of points and a new cap then see where we are at.
FWIW - All the Buick 4-speed transmissions I've decoded for the registry have been M-21s. Are you making it to Cecil Pat? We missed you and Dustin at Lynn and Paul's picnic.
Marco, I am making a brilliant effort to attend with the old beater. I am closing in and hoping we can do it. I have been thrashing every night trying to get it going well. Hope to see you all there as well as bring some extra friends as well. Sorry I missed Paul's bash,but other pressing things came up.
Update... I thought I was alot smarter than I was and I really screwed up. I had to for some unknown reason use different linkages on the 68 transmission compared to the ones that my M21 in my 73 used. Even the arms that bolted to the trans were different. Since I have a bench seat I had to use the stock shifter that the car came with.So In essence I had the linkages on the bottom of the arms instead of the top. I was essentially starting out in 2nd then 1st 4th and 3rd...lol Now I have it all straightened out,It shifts like a badass. I will say by using this tranny,its like the 3.42's were swapped to 3.73's or 3.90's. It cruises at 60 mph around 3200-3400 rpms.Has all kind of low end pull too.
It takes a real man to admit that one. :beer Thats a classic but i am glad you figured it out and are now having some fun. You sure had me puzzled on the swap results you were indicting to start with.
Actually, I thought it was weird and as soon as I got the hang of it,it was kinda funky...lol It really made me think when I slapped it into 4th and broke the tires loose...
