Ssssooooo.... Not blaming the shop by any means... This is most likely purely coincidental. I got my terminator back today after a kenne bell 2.2 swap, 26 spline, clutch, flywheel, TOB retainer sleeve, throw out bearing, firewall adjuster and quadrant. Without going into great detail... Transmission work was done first, Then the Kenne Bell... Them when loaded with the start up tune, the car was road tested and gracefully tested on the rollers before live tuning. The car did 4 hits on the Dyno, none of which showing the grinding from 3rd to fourth... Upon the car getting final welds on the same frame connectors... I took it for a test drive. Every time I hit fourth...grind. Well first time I rolled it off as not driving a stick for 6 weeks and getting used to the new clutch and single blade throttle body set up...third time it happened I started double clutching and limped it back to the shop. While in neutral without moving, you can start it...clutch in, pull it into fourth. No grind, clutch out, clutch back in, pull it into fourth, it grinds... It doesn't grind from 1,2,3,5,6. Only from neutral when idling... That's going from 1,2,3,5,6 to 4th I was running Amsoil ATF and I know he changed the fluids to RP synchromesh... My thoughts: A) shit happened and 4th gear synchro got burnt up after 2.2 Kenne Bell rage on my 33,486 mile Terminator. B) Shop incorrectly installed Liberty 26 spline since the 3rd and 4th gear synchros ride behind it and things have to be marked before reassembly (shop is reputable by far so unlikely) C) 4th gear got too 'lubricated' from new RP synchromesh... I know Tremec has advised against running synthetic in their Transmssions. Plan of attack: A) Tomorrow morning I plan to drain T-56, looking for metal or pieces of stuff which were once part of my glorious happy gearbox, deliver a bottle of Amsoil transmission flush and put some old, non-synthetic 1980s dextron III in to see if the grind goes away. B) If anyone knows if D&D Transmissions actually have the T-56 Magnums located at their HQ in Michigan, please advise soonest! I'll take off work and run to Michigan to get a 2.97 first gear T56 and then build a spare. C) Smartcar (just never happening / filler / needed a third option) Thanks all!