Haven't been here for awhile, been messing around. Thought I would try to make a tranny adaptor for a 371 to a 200-R4. I like the old cast iron Hydros but I also like deep gears and overdrive for a reasonable cruising RPM. A 200-R4 lets you have your cake and eat it too. Also a 200-R4 when worked on by the right people can be one tough mutherfucker. So here goes. Rob the torus cover out of a cast iron hydro and you have the start of a bell housing. Cut the center out of it, weld in a ring with the bolt pattern to match the front pump of a 200-R4. Cut the front flange off where the 30 bolt holes are. Use Olds bell housing off a stick shift or hydro and use as pattern for front plate of new bell housing. Pics will make more clear. Front pump of 200-R4 will have to have ribs cut off to fit inside flange. Plate will have to have hole cut for interference fit of torus cover so as to be welded together. Distance from back of flange to front of plate has to be calculated to be 1/8" longer than crankshaft to front pump. Torus cover is 12" diameter and stock converter will not fit. Solution is to have custom made a front wheel drive converter modified which gives you a 9" diameter in any stall you desire. I had one made by a converter company. Use stock flexplate and flywheel to avoid having to mess with starter. Flywheel is drilled with 3 holes for converter to bolt to. Nose of converter is a little too large for the stock flywheel opening so center of flywheel must be turned out a few thousandths. Stock flexplate can be used to bolt to stock flywheel. Now if your yardstick hasn't laid out in the rain and warped; flexplate, flywheel, converter, flange, hole in torus are all concentric. Oh, forgot to tell ya, you must whack aluminum bell housing on 200-R4. Now the whole mess bolts thru the front pump bolt holes. Have your local guru build you a double trick throwdown 200-R4 and you will be cruising easy with 4.30 gears. This will work on 350's or 400's also. Cadillacs benefit too. Pics will make more sense of this I hope. Depending on machinist cost or if you have a lathe you can get out pretty cheap except for the converter, which runs about $350.00. I had fun.
nice work Jerry! you should make a couple dozen of those and sell'em in the classifieds here,i can't seem to convince anyone that cast iron hydramatics are any good
my dad will love this one. He is getting ready to put his 371 into his 40 sedan and wants a better tranny...
Rite on good tip. been lookin into rebuilding trans for my pop"s 64 super88 but he might like this better.
The Jalopy Journal
