Here I go again.
First, a little history.
Original transmission. 1986 IROC-Z TPI. Stock. 150 000 miles. 3-4 clutch failure.
1st replacement: from 91 full size car. All work performed by (seemingly ) reliable technician. Disassembled and tanked. Reassembled with: Noyo Hi Rev pump kit, .500" pressure valve, Corvette servo, b-body repair kit (3-4 shift), mods to seperator as per B&M shift kit info.
Performed satisfactorily until the over run clutch that gives engine braking in manual 1-2-3 let go. Reassembled by the same tech however there was now an annoying vibration in park, neutral and mid rpm cruise ( more on that later).
2nd replacement. From 92 passenger car. History unknown. Reassembled by myself with the same components as the 1st replacement with the exception the Hi Rev pump kit. Performed reasonably well however on medium to heavy throttle in 3rd or 4th, the transmission would flare somewhat. WOT at the track wasn't a problem. Eventually that transmission failed in the 3-4 clutch.(Still had a vibration)
3rd replacement. From 89 IROC-Z. Less than 100 000 miles. Reassembled by myself with the same components as the 2nd trans.
Made 3 or 4 quarter mile passes. Worked great. 3-4 gears disappeared on the way home. Get to the shift point in 2nd gear (part throttle ) and then it shift into nothing. Like all the others. The vibration is gone though.
Always paid attention to the tv cable adjustment. However it could never be adjusted as per factory spec. I always needed to pull the cable out of the housing by 2 or 3 notches or the trans would stay in gear until 6000+rpm.
What's the scoop with these transmissions anyway? Am I missing something basic or is that the mods I have just can't support 400ft/lbs?