Wes, I drew some pictures to help clarify. The T5 usually needs a spacer if you keep the original 14 spline shaft because the splines are not cut long enough to allow proper clutch disc travel. The spacer moves the entire T5 back further and that functionally adds a bit of extra room for the clutch disc to travel away from the flywheel.
In my drawings, distance A must be a few millimeters less than distance B. Measure distance A with the spacer plate on the T5. Or measure distance B with the spacer plate on the face of the bell. One or the other, but not both.
If A is less than B you should be able to make the clutch disc release.
If your bell has an inspection cover, then another way to check all of this is the remove the pressure plate from the flywheel and bolt the T5 and spacer plate to the bell with the clutch disc on the shaft. If you can slide the clutch disc along the shaft away from the flywheel enough to see daylight pass between the disc and flywheel, then it’s all good.
Lugnutz, Thanks for your time and drawings. Not sure what I was reading when I measured but when I returned to the barn this morning to re-measure I realized that I read my tape wrong. Turns out that "A" was only 1/4" larger than "B", so I only need to shorten my throw out bearing retainer collar by about 1/2" and possibly ream the clutch disc splines a bit to create the space it needs to slide freely. I don't think I will need to shorten the tip of the input shaft since it only measures 1/8'' longer that the depth of the bushing bore and the thin spacer should move it out that far, but I still can shorten it if needed. Stopped in at FLAPS Friday and picked up a complete clutch pack for an S-10 for $100, thinking I got a great deal. Turns out the pressure plate is too small, throw out bearing may not be compatible and not sure how to extract the pilot bushing to see if the one in the kit will fit. So, maybe not a bargain after all. I am sure they are tired of me buying parts only to return them a few days later. Asked them if they sold the friction disc first and they said no, only the complete kit. Looks like all I will be able to use is the friction disc, which hardly seems worth $100. Does the original clutch lever have a retainer to hold the TO bearing? I don't find one in my salvage parts. If it had one I think the machine shop may have lost it. Thanks for your input.
Here are some options. I have a slightly used 14 spline clutch disc that you can have for free. Just pay postage. NEW Clutch Disc Options You should go with 11” if at all possible. The weight of your truck might cause the 9 + 11/16” disc to slip. 1988 Astro van with 4.3L engine clutch disc – 14 spline and 11” Option 1: M-PACT clutch systems part # 384212 from Rock Auto Option 2: SACHS BBD4212 from Rock Auto 1984 S10 2.8L V6 uses 9 + 11/16” 14 spline clutch disc
Wes, Lugnutz has laid out the facts of how to make your conversion. He and his site were my goto when converting my '51, 3600 to T5 sweetness.
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 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'm using the '88 Astrovan 4.3 clutch. It actually measures 10.75". 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.
Thanks to both Lugnutz and moparguy, I really appreciate the input. I'm gona do some research on the bigger clutch disc, and I do appreciate your offer, Lug. I work a part time job so I'm busy until my day off (Thu.) So, I guess I need to order a new '54 3600 throw out bearing and at you guys' suggestion a larger than 9" (14 spline) clutch disc? Just to clarify, I am not using a SMC. I'm using the machine shop rebuilt 235, bored .060 over, with a Bulldog cam, dual 2 bbl carbs, and Williamson dual headers, all purchased from Tom Langdon, and I installed an S-10 rear end. Is that enough to justify the larger clutch disc? I don't have a problem in purchasing one, just want you guys' opinion if it is warranted. I don't plan to haul anything 'cept ****. I have received and installed the necessary bracketry to mount A/C, P/S, alternator and water pump from a vendor in WI, along with the 2 groove harmonic balancer. Just trying to get the T5 tranny installed. I read a post about installing studs in the top holes of the bell housing, to slide the trans onto, which sounds like an awesome idea! Lug, if I want to take you up on your offer, how can I get payment to you? Does my email address show or can we send private messages? Still a newbe and not sure how all this works. Wes
I can send the disc and you can mail me a check or PayPal. Either way. Make sure you have a flywheel that can take the 11” clutch package. These two pics show a rusty flywheel that only takes the 10” standard clutch package. The second pic shows one that takes the 11” clutch disc. You can see the holes are closer to the edge of the flywheel.
Looks like after measuring my original '54 3600 4 speed clutch, it measures 10", so anything over that won't work for me in this situation. Probably stay with the 9 3/16 S-10 disc unless I can locate a 10" one. Have not looked yet. Tried my new P/S pump tonight and it appears to be metric, so probably be sending that back. Getting pretty frustrated with all the inconsistencies. Someday I'll get there...
Lug, Thanks for the info. I watched your slide presentation but don't think I want to go to all that trouble. I will probably ending up just taking the clutch pack back to FLAPS and seeing if they can get me an original throw out bearing for my ' 54 clutch and order a S-10 clutch disc on line from some other source. Have read that lots of guys have had satisfactory results and feel I should as well. Not gonna be a daily driver, work horse or drag racer. I do appreciate your input and expertise, thanks. Wes
moparguy, I got my T5 tranny mounted to the bell housing and installed in the frame after raising the cab, and all seems to work properly. I can see space between the flywheel and friction disc when actuating the clutch lever. My concern now is getting the proper drive shaft to connect to my S10 rear end. I haven't measured yet but have read of other guys doing away with the carrier bearing. What did you go with? Custom made or salvage yard part? My 54 3600 is a long bed if it makes a difference. Wes