hey all, I'm swapping a 460 into a 78 manual trans replacing a 400. Question is does the 400 bellhousing need a spacer and if so how thick? Hope to hear from somebody having actually done this particular swap Also did you encounter any problems with throwout bearing or fork? I'm using the 12" diaphragm clutch. Thanks in advance Trey

 

Well didn't get any good answers so had to learn the hard way,here's what I've found: 1) The 400 and 460 bellhousings are the same pattern but the lengths are different 400=6-1/4",460=6-7/16",This additional length compensates for the thicker flywheel on the 460 which moves the pressure plate and disc back towards the trans. The 460 also uses a special pilot bearing. A 400 bellhousing might could be used but not without modifications to the casting to clear the flywheel and shortening the input shaft bearing cover and possibly the input shaft itself as some cranks might not have enough clearance. Check your engines thrust before and after mounting the trans! I had a friend who did this and burnt up an engine as the crank was forced into the thrust bearing. The automatics interchange with no problem if used with the correct flywheel.trey gorbett/ 78 F250-Bronco Hybrid "SuperBronco" 460,NP435,NP205,Dana60 front,Sterling 10.25 rear,4.10's, 17/40x16.5 GroundHawgs http://communities.msn.com/treys4x4

 

Have a machine shop put your flywheel on a lathe and remove enough from the face of it so it is the same thickness as the 400 flywheel you took out and it will work. I did this to mine and it worked out great.

DennisPalmer

 

Tahnks Dennis, I had considered that but I want to retain the mass of the 40# flywheel, I lucked out and found a Lakewood steel bellhousing for a $100 and put that into it, everything matched up perfect after I made some 1" spacers for the bellcrank bracket. Won't hurt having the extra protection (seen some pics of a clutch explosion on one of the other sites,not pretty!).......trey gorbett/ 78 F250-Bronco Hybrid "SuperBronco" 460,NP435,NP205,Dana60 front,Sterling 10.25 rear,4.10's, 17/40x16.5 GroundHawgs http://communities.msn.com/treys4x4

 

If it is a pre 78 460 a 390 flywheel will bolt right up no mods needed.

 

 

Why wont a 78 460 bolt right up with a 390 flywheel????