My 64 c10 has a factory top-loading 4-speed in it with a granny low which pretty much makes it a three speed for daily driver duties. I'm trying to build a hot rod and have no need for the granny low. I want to keep this build all 60's to early 70's vintage parts and all GM if possible. I'm looking at M21/M20 and T-10's but I want keep the factory bench seat because it is in good shape and I like it. The question is: Has anyone tried this? Will the shifter on one of these clear the bench seat or will I have to put buckets in it? Or is there another option? Thanks in advance. Posted using the Full Custom H.A.M.B. App!
I've used Muncies in Chevy Belairs with the bench seat and it was fine. You may have to find a stick somewhere at the very worst since the truck seat is a lot higher than a passenger car. Or bend down to shift, seen that before...
I've definitely got no problem buying a longer shifter if need be, I'm mostly just concerned that the hole in the tunnel might have to be too far back for a bench seat. Posted using the Full Custom H.A.M.B. App!
Don't forget, the truck bell housing may have a larger throw out bearing collar hole than a passenger car. Adapter rings are available. If you have a Hurst bolt on stick, the Tri-Five, bench seat shifter stick may help. I have one I bought new, but it won't work as designed in a Tri-Five as the stick still hits the bottom of the seat; it should be fine in a truck due to more floor board clearance. I am Butch/56sedandelivery/.
Why not keep the existing tranny... and change the rear gear ratio instead? That'll make the 1st (granny gear) useful and give you a highway gear as well.
I have done a few Saginaw four speed installations with no problem. Buy the Hurst installation kit for the shifter. Not sure about muncies, but I have seen quite a few done with the stock bench seat. The throw out bearing collar hole got bigger in 1967, so you are good with your existing bell housing.
yeah, you can bolt in the 4 speed car transmission...although you need to use longer bolts and nuts on the bottom two holes where it mounts to the bellhousing. Years ago when I put a saginaw 4 speed in my 59 pickup, I used the long Hurst handle, and cut a notch in the bottom of it, bent the handle forward, and welded it back together, to clear the seat. you'll have to play with the driveshaft too, you know. And the parking brake crossmember might be in the way of the shifter. Always a few little details to get in the way.
I have the sm420 transmission in mine and I just changed out the rear end gears. I still never use 1st but I can cruise highway speeds with no problems now. I went from 3:73 to 2:73. Best move I ever made. It's a 64 long bed
Thanks guys! That's what I needs to know. I didn't want to bother tracking down a Muncie just to find out it won't work. The minor details, like the park brake I can handle. As far as the driveshaft, I planned on needing to have one built, luckily a friend of mine has been building driveshafts professionally for 25+ years. Posted using the Full Custom H.A.M.B. App!
I saw a shifter on ebay yesterday I think and it has a curve it it that should match the seat . it was around $25. I almost bought it for a spare.
The M-20 I have has a 2nd set of mounting holes for the shifter which move the body forward about 2 inches. Using a high mount with the arm running straight forward I had to space it out about an inch to clear the speedo cable housing. Would have had to cut off the bracket to put a cable in though. I just use a tach for speed. jerry
Those trucks could be bought with a 3 speed overdrive, then go to a column shift and the flat floor pan. cool.
I use my granny low 4 speed while pulling a trailer. It is also fun for making lots of noise at runs, 2000 rpm sounds great but you are still at a fast walking pace.
I have a newer truck with the SM465, and it has 3.21 rearend gears, 3/4 ton, and too small of an engine. I use granny all the time.
no need to swap your bench for fugly buckets which only looks good in Vettes and Super Sports. My nomad had the original bench seat with a 4 on the floor and I never had problems with it.
You can make a bracket to push the shifter closer to the bell housing if needed. Did it on a friends model A with a saginaw 4spd.
The rear change makes a dramatic difference. I had the old trucks with 4.56 up to a 5.38 ratio, not fun being wound out at 50.
The truck has 3.73 rear in it now, since I don't ever go over 55mph with it anyway and don't plan on taking it on the interstate, I think I'll just stick with the 3.73. If I change my mind later, so be it. I really just don't like the granny low and want a 4-speed I can really bang on. The truck trans just doesn't shift fast enough. Posted using the Full Custom H.A.M.B. App!
Nothing wrong with 3.73 gears in a real pickup. We had those in a 70 1/2 ton with a 307 and SM465 and it ran down the highway at real highway speeds and got 16mpg out on the road. It should be an easy swap and the granny trans should be easy to sell if it's still in good shape and you might even be able to sell it before pulling it as you can still demonstrate that it works good.
the granny boxes do shift like crap....I totally understand wanting a different 4 speed! and yeah, the 3.73 gears will work great for you.
My brother could shift a SM420 like it was a M21... he had this old GMC with a 327 Vette engine that went like stink. His had a 4.11 rear.
Haha this takes practice! I'm getting better in my truck, took a lot of grinding though OP, if you ever want to sell your SM420, hit up the 4x4 guys. They love those trannies.
Actually, I was thinking of keeping it in case I decide to build a jeep or something someday... Posted using the Full Custom H.A.M.B. App!
I was sittting right next to him more than once when he raced it. He said the trick to getting good shifts was a good cover assembly, which were available at local truck yards. Maybe not as good as rowing an M21, but impressive as hell at least to me.
i used to love these tranny's and my boss always told me dont use the clutch after take off and they would slide into gear at the right moment. summit has all kinds off shifter handles and even have them for bench seats
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