As far as the bell, it's for a SBF. I don't know if the Viper bell is a GM but I know it won't fit. D&D most likely made the bell housing, for SBF, but I hear they are really pricey as they want you to buy the whole tranny from them.

I'm not a drag racer but why couldn't you use an approved scatter blanket?

Yes, it requires cutting the tranny tunnel. I rasied mine 4" and ended up with a 2 degree downward angle.

The Viper spec tranny has a .50 6th gear. Why, I don't know but I guess cause that engine makes all kinds of torque. Just make sure your engine combo can run at the 2000 RPM you will cruise at. Hot cams, big valves mean poor performance at cruising RPM.

Well like I said I have the Richmond 6 also I've never looked at the t-56 until the last week or so for another project. I got my richmond pretty cheap for the simple fact the guy who bought it in the first place ordered some strange gear combo's for it. and his SBC was not up to the task of a 4.07 first (killer hole shot) 2.56 second so basically my 6 is a 5 speed I have the .62 final and I'm running a 3.55 center section in the rear on the street. It's turning 2250 RPM at 70MPH. I found a T-56 (gm) this last week rather cheap that I may dump into the wifes car mild 351 and all street cruising use. The T-56 is probably fine for most people but from what I've been reading about parts and what I have to do to swapto the T-56. The Richmond may come out cheaper in the end.