Engine/Tranny Bolt Pattern Compatible?

[Two48s]

My first question in this forum... I have a 48 GMC 1/2 ton with a stock drive train, but the motor is blown. Is the tranny bolt pattern the same as a small block Chevy, or do I need a different bell housing? I know there will be many other issues, such as exhaust to steering box clearance, and motor mounts. I have seen many other posts about those, but not the engine/tranny compatibility. Also, what about the clutch/pressure plate/flywheel? I have an engine from an automatic, but want to stay with the 3 on the tree. I know I will need a pilot bearing, but will the flywheel assembly bolt onto the crank of the SBC? I am trying to figure out as much as I can what I will need before I tear it apart. Thanks!

BTW - in another thread there was talk of "unique" names to places - how about the "Bong Recreation Area" in Wisconsin?

[JumboAMONGus]

i have a 56 with a 6 cyl, and its a diffrent bellhousing then a 57 and later bellhousing ,,but most bell housings from 57 on up to 60s and some mid 70s will fit v8 or newer 6 cylinders and still have the bolt to crossmember tabs on them ,

[dwcsr]

Originally Posted by Two48s

My first question in this forum... I have a 48 GMC 1/2 ton with a stock drive train, but the motor is blown. Is the tranny bolt pattern the same as a small block Chevy, or do I need a different bell housing? I know there will be many other issues, such as exhaust to steering box clearance, and motor mounts. I have seen many other posts about those, but not the engine/tranny compatibility. Also, what about the clutch/pressure plate/flywheel? I have an engine from an automatic, but want to stay with the 3 on the tree. I know I will need a pilot bearing, but will the flywheel assembly bolt onto the crank of the SBC? I am trying to figure out as much as I can what I will need before I tear it apart. Thanks!

BTW - in another thread there was talk of "unique" names to places - how about the "Bong Recreation Area" in Wisconsin?

Nothing from that engine will work with a SBC.

[Two48s]

OK. Thanks guys. So how do I figure out what I can use to adapt the SBC to the existing tranny? Will a later model bell housing bolt up to the old tranny? How about the splines for the clutch plate? I suppose I could just dive in and have a look. I was just trying to avoid that. I prefer to be as prepared as possible before starting something I've never done before.

[IndyBowtie]

Throw that old trans away. Too low geared! I put a t5 5 spd from an S10 behind my original 6 cyl in my '48 Chevy and now it resides behind my 283. You will love it!

[mknittle]

Originally Posted by IndyBowtie

Throw that old trans away. Too low geared! I put a t5 5 spd from an S10 behind my original 6 cyl in my '48 Chevy and now it resides behind my 283. You will love it!

sell it to a jeep guy to help fund parts.

[JumboAMONGus]

your stock tranny will bolt to a newer bellhousing ,and for the clutch its probly for a 10 spline ,,should all work im guessing i never looked i still have my original 3 speed sitting out side i forgot where i put it in the field hahaaa,,,im using a borg warn t-10 from a 62 impala ,,just change the bellhousing and but a new clutch and pressure plate ,and your gonna need a new flywheel for the small block chevy

[Two48s]

Yeah, I would love to put in a T5. But doesn't that mean a new rearend also too go with the tranny since the new ones have an open shaft setup? It would also mean modifying the floor pan for the shifter, pedal modifications, linkage modifications, cross member, etc. etc. I just want to bolt up to the original stuff if possible just to be able drive this 5 window occasionally for now. Then I can take apart my 48 GMC 3 window that is completely original and do a ground up for the wife to drive. Then when that's done I can come back and do the 5 window the way I want to. Must take things in steps...i.e.: Must make momma happy first!

[Two48s]

Cool - Thanks Jumbo!

[JumboAMONGus]

yeah thats true jeep guys and toyota land cruiser fj40s love the older trannys special the sm420 4 speeds ,i have a landcruiser same bolt patern as chevy