I have a 65 327 with a T-5 out of a 87 S-10 behind it. I have the 5/8" spacer between the******* and bellhousing. This is in a 51 "shoebox". When first put together I used a common chevy bellhousing with the clutch fork at 9:00 o'clock. Because the clutch pedal is on the floor, the pivot is down level with the frame. We built a triangular fixture to connect the two. This worked perfectly for about a year, being able to shift thru all forward speeds (5) and reverse. After about a year, I couldn't shift thru any gears. The "fixture" altho pulling the clutch arm back, it was also pulling it down, which put undue pressure on the throwout bearing, which in turn bent several pressure plate fingers (the reason for it not shifting any longer). I thought I had found the solution by switching to a Nova bellhousing which has the clutch arm coming out at 7:00 o'clock, placing it directly in line with the clutch pivot near the frame. With a new pressure plate and throwout bearing with a steel collar (the other one was plastic), I thought I was back in business. Upon startup discovered cannot shift into reverse with motor running (it just grinds). Can place it in reverse and start and then shift out of reverse to a forward gear. The Nova bellhousing had the small center hole, so I had it enlarged to fit the front of the T-5. Pulled******* and checked bellhousing opening for "indexing" (I had heard of indexing, but never knew anyone who ever had to do it). The bellhousing was .015 thousands out. Bought offset pins that go in the back of the motor (.014 thousands), thinking this was the problem (was told that if not indexed correctly, it could effect shifting). After installing the offset pins (we got it within .oo5 thousands), we thought we had the problem fixed. Upon start up.....same problem. Cannot shift into reverse with motor running. Shifts forward just fine. I know that the clutch "geometry" correct, the the throwout bearing is engaging the pressure plate enough. (laid it all out on computer) I realize that the reverse gear has no syncos, but it all worked before the mishap with the clutch linkage. I am at my "wits" end. Could there be something wrong inside the transmission? This isn't "rocket science"
If you have no problem shifting into reverse when the engine is off........but can't do it when the engine is running, then it sounds like your clutch is still dragging a little when depressed. Maybe a longer throwout bearing to change the leverage of the clutch arm, or an adjustable fork pivot might work.
Or even second or third.! I do that without thinking . First and reverse are not synchronized in my three speed. Ben
Your problem might be that the clutch isn’t releasing enough. You mentioned bending several pp fingers so it sounds like you have a diaphragm clutch, you need .030-.040 clearance at the disc. It may be possible that the clutch releases enough to shift synchronized gears but it drags just enough to prevent shifting to reverse. Drive a bit to warm up the clutch and check the clearance.
Why a 5/8" spacer? When I hooked up my T5 to a Chevy bell (using a '58 in my case) I used a 10gauge sheet metal spacer between the bell and transmission, trimmed the input shaft tip back around 1/2", and trimmed the TO bearing collar some prescribed amount (how much I do not really remember its been years). Is it possible you might be running out of splines on the input shaft for the clutch to move back on or hitting the end of the TO collar with the clutch hub if its too long? Also, my rebuilt '88 S10 T5 likes to grind going into reverse if I do not put it in 5th first. I had an '88 S10 with a t5 when it was a nearly new used truck, it did the same thing. I think reverse is touchy on them in the best case and with some wear they only get worse so be gentile on it.
I pulled a T5 out of a blazer when I was living in Mexico. Tore it down because it was not shifting properly. I could find absolutely nothing that would cause it to scrape going into gear. Always in reverse and sometimes shifting through the other gears. The little truck had a brand new clutch and pressure plate. Finally out of frustration I lay a straight edge on the pressure plate. The brand new pressure plate was warped. Put a different pressure plate in and solved the problem. This is not doubt not the problem but it won't cost much to check.
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