I installed a t-350 last week with turbo action reverse pattern valvebody transbrake and a 3500 stall converter.Also installed a gm 847 and a tune to match the mods. pcm forless also supposedly tuned out the tranny program. Problem is some times when driving steadily and upon acceleration it feels like someone suddenly hit the brakes on me almost like the transbrake is kicking in, what the heck? about a month ago I also installed a ford 9" without abs provision and just pulled the relay under the hood could that cause it?It goes away after a few seconds but its there and is scary! The way this trans brake works is you hit the shifter handle button to engage reverse (activating the selonoid) and it lockes it up in any gear.Also dont have reverse unless you shift into reverse and press button, I have one side of the selonoid grounded the other side to the switched 12 volt source(shifter button). Help!