Another "How Easy it is".
My approach was no spacer. Shorten the input shaft to match the original SM420 shaft length. Same with the input shaft housing. Use a Dewalt angle grinder to lengthen the clutch splines in the input shaft. Then I took the input shaft to the bench grinder and removed input shaft material on the transmission side of the shaft splines until the clutch had sufficient travel to work without binding. I know this sounds like a recipe for input shaft failure, but keep in mind we're dealing with a less than 100 hp stock 216 engine (in my truck anyway).
Clutch disk. I used an '88 Astrovan 4.3 clutch purchased from Rock Auto for less than $50.00. It actually measures 10.75". The stock pressure plate works fine .
New throwout bearing.
Drilled out tanny case mounting holes to .5", used stock bolts in top holes and two new bottom bolts 2" long.
That's pretty much my story. The original thread is
here.8 years and 20,000 miles and still happy with the conversion. I did swap T5's to get a better (for me anyway) ratio .72 5th gear.
Good Luck,
RonR
