I am purchasing a 72 skylark convertible and just picked up a 4 speed set up from a 68 cutlass. (Muncie m20, driveshaft, clutch fork and more miscellaneous part). I am a fairly handy as have pulled a few Buick motors and automatic transmissions over the last 25 years.... but I would not consider myself a mechanic or technician... I am hoping folks can tell me that the 3 speed linkage, neutral safety switch, reverse lights and most everything will be the same for the 4 speed? I would assume the stock 350 will have the crank drilled already? Also, does anyone know if I can use the same crossmember and transmission mounts etc.? I always wanted a GS convertible 4 speed so I think this will be the closest I can afford. Thanks for any tips or info etc.
I recently did an auto to 4 speed conversion and some its still fresh in my noodle. based on your description of 3 on the tree I am assuming you are referring to a column shifted manual transmission. the x member should be the same for both 3 and 4 speed manual trans cars. Your crank should already be drilled for the manual transmission that you currently have. You may need a different size pilot bearing, but I have both a 3 and 4 speed manual transmissions and both have the same diameter imput shaft. Not sure if that 68 driveshaft length will be right, but it could be and I believe the one with your 3 speed car may be the right length but the 4 speed output shaft may have more splines on the yoke than the 3 speed. so you may need to use the 68 driveshaft yoke. I am unfamiliar with The 3 speed manual column set up so I cant tell you what is the same but I assume you can use the existing reverse lock out linkage on the column which goes from the key switch through the column and down to the transmission. I used a 4 speed column on my project but the automatic columns lock out linkage appears the same as the 4 speed. You should have the right neutral safety switch in your column for a manual trans car and I believe that works of the same linkage as the reverse lock out. I think you should be able to modify you column to work with the 4 speed and you probably want to remove the shift lever on the tree. Good luck!
I can almost guarantee that the block isnt drilled for a Z ball ball stud. The crank is probably not machined fully either. Your going to have to pull the motor, measure 3 times, drill the block and tap it. Not easy but do-able. You may also need to machine the pilot bushing either in length or diamter A 442, 455 Olds Z bar is the same as a 350 Buick, so they're readily available. Bellhousing is a 9735581 and is readily available (I have an extra if you need it) 4 speeds dont have neutral safety switches. The neutral safety switch on the bottom of the column is replaced by a back up light switch. A 4 speed uses a clutch safety switch instead. You may be able to adapt a GTO or Chevelle style switch. The only expensive part is getting a 4 speed flywheel for the 350. I have a spare Hust C/P 4 speed shifter if you need it
Jason, Of all the 350 motors I have owned,only 1 wasn't drilled. I would bet unless it's a blue motor,it will be drilled...That shifter isn't a 5335 by chance is it??
All the non drilled ones must of been shipped to NY! :spank:ou: I have a couple 5335's, but for the OP's purposes I have a nice Hurst aftermarket shifter that is a direct replacement for the OE GS shifter. No sense in using a 5335 on a Skylark (no offense)
He wasn't who I was concerned with...lol And, my Skylark would Love to have an original 5335...All I need for a complete setup is one of them, a 4 speed speedometer, and a floor hump. I have everything else...Plus many many linkages and such...
have any of u fellows ever seen or heard of 4 on the tree for a gm car. My dad purchased a new (Canadian) 1963 impala ht . I seem to remember reading in the owner's manual, and with a picture, that 4 on the tree was an option in the full size chev.
If the conversion is from a 3 speed manual to a 4 speed manual, which is what the title of the post implies, it should bolt right in. The safety neutral switch is replaced by a switch that enables the starter only when the clutch is depressed (70 and up) and that should already in place . The only tricky part would be the linkage that goes from the trans to the column for the shifter lock. The clutch stays the same. If he's going from and automatic it's a lot more work with clutch linkage and stuff, but the cross member and drive shaft are the same. There was an aluminum flywheel posted about 3 days ago. That's the one part that wont transfer from the Olds set-up.
Good info... however, I am a little confused... the car hasn't shown up yet... will be here in a week or so... just to be clear I am keeping the original Buick 350... I would assume: 1) if the 350 has a manual 3 speed already shouldn't the flywheel be a manual flywheel already and should work for the 4 speed? 2) the crank must be drilled already for the 3 speed, isn't it the same for the 4 speed? 3) There is a clutch pedal to work the 3 speed on the column so wouldn't the block already be set up and installed with the correct pedal set up, z-bar etc.? Here is a link to the car I am buying... one of the pics shows the linkage underneath... I think I see clutch pedal assembly/linkage? http://oceansideautosales.com/Used-1972-Buick-Skylark-Convertible-Newport-NC/vd/15482648 Thanks for the help.. does the link or description above help?
The answer to all three questions is yes. You'll need to cut a hole in the floor for the shifter. Somewhere around that time they also locked the shifter when the steering locked. You may have trouble finding that piece of linkage but it's not necessary to have it. It should go right in.
I may have mis-read the original post. I thought you were converting from a three speed automatic. My apologies.
No problem... thanks all! I choose the "3 on the tree" as it appears it will be an easier convert than going from automatic to manual.... I'll have more questions I'm sure in the coming weeks
Did you buy this car sight unseen? Three on the tree is very rare! 95%+ of all Buicks made after 1954 were automatics.
It is from a dealer..... 87 pictures, of everything from the trunk, transmission, pedals, motor etc. plus they sent me 3 videos of the car running..., body, trunk, frae, engine etc... It ended up being a $13,500 car and not a $40,000 car so I believe worth the risk... I am going to keep as much of the rest original if I ever wanted to go back... the only big deal is that it will have a trans hump for the 4 speed which could be filled easily.... I have seen some Chevelles with 3 on tree but this is the first Buick from 70-72 I have seen and definitely the first convertible.... so yes I agree with you that it is rare...
In my opinion,there is no way I would swap that to a floor shift. When is the last time you ever seen a 3 speed on the tree??? The coolness factor is already there.. Please post some pics when you get her there..I couldn't get the link to open..Please,rethink the 4 speed swap...pretty please??? Ok I am no good at begging...lol
Haha....... Sorry I think I'm stuck on converting to a 4 speed. I'll keep the column intact so again it will only really be the 4 speed hump being added which can be removed easily. The 3 speed will remain close by if I ever wanted to convert back.. Jason, what do you want for the after market shifter? (not sure how good the one on the M20 is yet... still waiting for it arrive) Thanks
Pay attention to your ratios. If it's a 3 on the tree it probably has a 3.08 or 3.23 rear so an M20 that has a 2.56 first gear would work nicely. A M21 that has a 2.20 first gear would not be enough first gear, you'd probably use a lot of clutch pulling out.
Please post pictures of your car and the project once you get it! Sounds like a neat car! Make sure you keep all the original parts together because like everyone has said, that is a rare car. Just as a side note....I am using a 1977 (Blue) 350 block for my 4-speed and the hole was drilled for the z-bar bolt. I lucked out. In order to get the pilot bushing to fit, I had to sand down the crank slightly. It was just off, I forget by how much but very little, but I finally got it to go in. Take your time with it, have fun, and try to have as much patience as possible.:laugh::3gears::TU:
