Our family has a 71 Skylark, currently with a 455 and 700R4. I have someone that is offering me a Tremec 5 Speed. What type of challenges am I getting into if I go down this road. I.e. pedals (Will Chevelle Work?) Clutch components, cutting the hole in the floor, boot/shifter for bench interior... anything else I am forgetting?
If I'm not mistaken, I believe the tremecs require some fairly invasive transmission tunnel surgery as they will hit. The hump isn't big enough in a 70-72 Buick a-body to let the trans sit where it needs to.
Chevelle pedals won’t work without either the entire bracket they hang from or you’ll have to drill out the Buick bracket. If I remember Pontiac a body pedals are the same as Buick but don’t quote me on that.
http://www.4speedconversions.com/67-72_bop_pedals.html This is probably the best solution for pedals unless you must have an exact original. The chevelle one has the “pin” built into the clutch pedal and slides thru the bracket where the BOP uses a bolt.
It is possible to trim down a tremendous to help it fit under the tunnel better, looked into this for a Mustang project we have going on. It's not cheap, and if you happen to.brake the case later on you have to pay again. Be very careful and know and plan your gear ratios of trans and rear based on tire size and hp level, if you get the wrong trans you will up being stuck down shifting on the highway to be able to pass, or have a 1st gear tht just blows by.
Here go... they have template and sheetmetal premade https://shiftsst.com/articles/cat/general-motors/post/gm-a-body-1968-1972/
I have a tremec tko600 attached to my 350 in an originally auto 70 Skylark. I purchased the kit from SST ( previously Keisler). Gives you everything except pedal assembly, flywheel, and bellhousing. The sheet metal for the hump is made for most 68-72 A- body's, so I would definitely suggest cutting only as much out of the tunnel as necessary. If you follow the template, it will work, but definitely cuts out more metal than necessary. I recommend the hydraulic clutch set up, unless you've already purchased the clutch rod, z bar, fork, etc. Hydraulic clutch also allows more room for headers. Also, USE a pilot bushing, NOT a pilot bearing. The bearing requires your bellhousing to be perfectly centered with your crank. The bushing is more forgiving and won't suddenly fail.
Another option if only for information. http://www.hurst-shifters.com/driveline-conversions/ I got my pedals, z-bar, clutch, bell-housing and shifter from Dave Kleiner. He might be on V8 BB.
Update: I tried to order the template and sheet metal from shiftsst, but they replied back those items are only available if you order the entire transmission from them. So I went on Hurst and placed an order today on their site.
If you can source the clutch pedal, it will bolt on with a longer bolt to your current bracket and brake pedal. Heres the longer bolt and bushings https://www.opgi.com/skylark/G241778/ Also, Pontiac uses the same safety clutch switch which prevents starting with the clutch not fully depressed https://www.opgi.com/lemans/G241442/ Closest shifter boot to Buick is Olds https://www.opgi.com/cutlass/C240596/ And the retaining ring https://www.opgi.com/cutlass/C240597/
