[81scottsdale400]

hey guys i need to know what i need and how hard it is to take a 1980 GMC half ton 4x4 with a 350/350 combo and swap it out with a standard chevy 4 speed manual transmission please let me know thanks

[a1supersport]

Other than the usual Clutch pedals/linkages, bellhousing/clutch/flywheel...which 4-speed are you looking at? The typical SM465 (granny-first gear), or a car-type 4-speed (Saginaw/Muncie/ST-10)? If you're going with a granny-first, probably best to find a donor-truck/blazer/suburban to get ALL the parts from.

[81scottsdale400]

im going with the sm456 with granny first i wanna do this cuz my truck was a 1980 chevy scottsdale that i build a 400sbc in high school (im only 19) and it was a 4 speed and i loved them. but thanks to a stupid 15 year old kid and running a stop sign sideswiped me and totalled out my truck and i lost everything so my new one is an automatic and id rather drive a 4 speed again so if i can do this with the help of you guys let me know id appreciate it alot

[Dagwood03]

The four speed trucks have a special little bracket located on the drivers side top of the frame under the cab fire wall that the balljoint of the pivot rod bolts too... You need to configure that bracket if your gonna run a mechanical clutch... You can run a hydraulic clutch but I've always had them blow at bad times... Mechanical linkage only wears out two main parts... Knees and shoulders... There is a hydraulic and mechanical linkage bell housing too... And ya have to make sue you have the right spline 465 to fit transfer case... I swapped my 86 short bed... I found a fine spline output shafted 465 for my 208 transfer... I wish I woulda went 465 205 transfer but I like my transfer case shifter better... Aside from the flywheel clutch pressure plate and basic stuff that is the problems I ran into... If I remember anything else I'll let you know...

[81scottsdale400]

thanks guy does the ball joint bolt to the frame or do i gotta weld it on and how would i find out which trnasfer case i have?

[Dagwood03]

there's like a piece of pipe with to ears welded on it... One ear on each end of the pipe... And the ears point in opposite directions... That's the best I can describe it... Anyhow there's a ball that bolts to the block or bellhousing ( I forget) and the other ball bolts to the bracket I mentioned above... then one ear on the tube has a rod that comes from the pedal and on the other tab a rod goes to the clutch fork... that's the best I can describe it... As for transfer case that would depend upon shift pattern, is the case aluminum or cast, and is it slip yoke tail shaft...

[Dagwood03]

Oh yea duh?! I'm dumb... Look for a little circle badge on the transfer case about the size of a silver dollar... It'll say somewhere on it something like MODEL and then like NP208 or NP205 so on and so fouth... Do that first...

[75gmck25]

You need to find a donor truck with a working 4 speed, transfer case, and driveshafts, or you will spend a lot of time putting the right pieces together.

The output of the TH350, TH400, and 4 speed have different spline counts, and the count is not even consistent across all years for each trans. This means the transfer case to transmission adapters are different for various trucks. Also, since each transfer/trans combo is a little different in length, that changes the driveshaft length for both front and rear.

You should have an NP208 transfer case, unless someone has swapped it out.

Bruce