Rusty, I got mine thru either American Classics or Classic Parts of America(ChevyDuty). A firewall grommet set is available. My burb has a 3.73, I really haven't driven it much(still doing bodywork) but I had the combo in my fleetside using a 3.42 rear-love that overdrive! Its a completely different truck compared to the TH400 that was in it. Brian
