The diesels use a different stall speed converter than gas ones too,its got a 6 bolt flexplate pattern,but 3 out of the 6 will bolt to a gas engine's flex plate --in fact,GM used the diesel torque converters on some gas applications also,I have seen several G series vans with 292 sixes that had the 6 bolt converter,some in BB trucks like C-30's with dump bodies,and I've read a service bulletin on some GM trucks in the 80's that had "low speed shudder" problems ,the fix was to install the 6 bolt diesel converter ..
I think the stall speed is so close a lot of people wouldn't feel the difference on the 3 versions they had--what I notice most in the diesels I have is the tranny feels like it wants to "creep" at a stop light more than a tranny in a gas engined truck,you really have to kep your foot firm on the brakes,and when you accelerate,you take right off,the engine doesn;t seem to wind up first ,then go....personally I prefer an automatic that feels like its not slipping at all,I never liked the slippage a high stall speed converter delivers,to me it sounds like its just wasting fuel and not really doping anything good for the tranny--heats it up and kills it faster maybe?..
I know guys who have swapped 700r4's into their diesels ,that originally came from gas engined trucks,they claim the higher stall speed isn't that noticeable ,maybe it feels a little peppier even,having it rev a bit higher before launching..they could only use three out of six bolts on the flexplate (just as a gas job would)so far none have had any problems with "only" having 3 bolts--if a 454 gets by with 3,I doubt a 6.2 would be any more powerful..
Turbo 400's from factory BB vehicles usually have more clutch packs and clutches than one from a small block,maybe some stronger sprags too..I have one from a 74 Monte-Carlo 454 sitting in my shed,been hoping it might mate to my NP208,but I think the tail is going to be a tad too long...be a nice spare for my truck or maybe a replacement for the dying 700r4 in my Suburban..
O like the fact GM stuck with one typical bell housing on so many years and engines..sure makes bolting an engine in from "whatever" year you can get one from a lot easier...Fords suck in this respect,seems they had a lot of "specific" bell housings and you were S-O-L if you didn't have the one the motor came with..
