Th350 to Muncie Swap - 72 Skylark Custom


Hey all,

Been gathering parts to swap out the th350 for a Muncie in my 72 skylark 350-2. I have a lot of questions before I do the swap in another week. And as you know, working on a Buick isn’t the same as working on a Chevy, and there just isn’t the same information out there. Hopefully you all can help me out.

First question: is there a shifter hump? I’ve only been able to find a few photos of skylarks with hurst shifters. I have seen photos in which the shift boot contours to the standard hump. But I’m not sure. I don’t have a console. Will the linkage clear the hump without installing a new shift hump? What shifter boot is required?

second: I am having a hard time finding the correct clutch linkage. it looks like the parts place has a clutch linkage kit for a 70-72 Buick. Is the clutch linkage really that much different than for a Chevelle? The price is about 2x the amount, So just wondering what the differences are...

aside from that... research suggests a 66tooth flywheel and a 10.5” clutch. does that sound right? I’ll also need a new starter.

hurst shifter should be here this week. Just trying to find the right info to go and order the rest of the parts.

many thanks,

The shifter boot for cars without a consolette is GM part no 389905. There are some suppliers online showing this piece is being reproduced. Attached is a page for the shift linkage parts from the Buick Master Chassis Parts Catalog.

The clutch linkage design of the Skylark is similar to the Chevelle. Many of the smaller pieces have the same part number for Buick as Chevy. The larger pieces like the clutch pedal arm, rod, and equalizer are not the same. Attached are some exploded parts views of the two for comparison.

The ring gear on the 350 engine has 160 teeth. Manual transmission cars used a cast iron flywheel vs. the stamped steel flex plate seen on automatics. The 455 engine ring gear has 166 teeth. The shop manual shows the 350 engine clutch plate size at 10.4" -- almost the same as the 10.5 you found. The starter is the same for manual vs automatic usage.