Just picked up a 64 GMC pickup thats in pretty good shape. Its got the stock 305 V6 in it with a granny 4 trans. The mills in pretty good shape, but I'm sure it won't last forever. I'd like to put a 350 in it as they seem pretty solid and can handle modern roads a bit better. How difficult is that swap going to be? I imagine I'll need new motor mounts, but what about the trany? A 350/350 combo would be cool, so whats the total project going to look like? Any help would be great, I ran a search but didn't see anything. Thanks, Bryce
Its not even a swap they are both the same size engine. You should be able to pull everything off of the 305, bolt it on the 350 and put it back in. 2 people could probably swap the engines out in a few hours Gary
you should be able to find a truck that came stock with a v8 that has everything you need to swap it out as far as mounts, brackets, crossmembers. You might have to modify for the trans crossmember, since most trucks had a standard trans. I thought the same thing at first..SBC 305 to a 350..easy..
proabbly will need springs, motor mounts from another truck maybee use angle iron for a rear trans mount and will need proabbly a 1/2 ton driveshaft cut to length maybee the rear crosmsmber to mount driveshaft and quite likely the gear ratio will be off it quite likely has a 2 piece driveshaft did this on a chev 1/2 ton went from 4 speed to a 3 speed and it was not without problems when you remove the boat anchor of a v6 I am sure the front will raise up going to a SBC if you are going to leave the 4 speed you will need a chev bellhousing may be the time to buy another chev V8 truck close to your year and strip it for parts
I haven't seen a 305 V6 in a few decades but a guess would be that you'll need the frame brackets and motor mounts off a similar year SBC Chevy or GMC for starters. Might even use the same brackets just in different frame holes. The rest should fall into place like bolting one in any other Jimmy or Chevy PU.
See you learn somthing new everyday I was thinking SBC V8 305 Perhaps it will take the better part of a day. LOL Gary
Oh man, I was so excited for a minute, thought I had finally gotten lucky! So this isn't going to be a really easy thing to do from what it sounds like. Maybe I'd be better off to rebuild the engine and re-gear the rear end so that its a little better on the freeway. I'm not going for a fast truck at all, I just want something that'll go about 70mph for the freeway. Whatta ya think?
Bought a gmc in high school with one, the Olds 425 I replaced it with was a much more fun motor! (Dont ask, I dont remember what it took to get it in there.)
I have 2 or 3 of those trucks with SBC's in them, so if you can't find parts by you or need some pics or?? Let me know.
It's practically all wrench work, the only way it could be any easier is if it was already a SBC and auto trans.
some of the GMC pickups come with a pontiac V8 also some big chevy trucks the ones with fender extensions in 1957 had 322 buick V8s and thay hauled **** and had tork kinda hard to miss the good old days of really cheep vehicles $25 would get you some running iron
Get the motor mounts from a 67-72 PU. Two of the three bolts are the same, so you will have to drill one hole on each frame rail. I used the original transmission mount and modified (dropped) it to fit a t350. If you have the low hump (floor) in your cab it will be a tight fit (the ****** will hit the trans tunnel). You will have to have a new or different drive shaft, and can't remember what I used. There is a lot of info on www.chevytalk.com Good Luck, Kathy
Thanks for all of the help on this. I'm not affraid of some wrench work on it, but I'd like to have it down for as little time as possible(I drive it a lot). I'll check around and see about the drive line. The p.o. changed the truck from the column shift 3speed to the 4speed, and when he did he cut out a LOT of floor, so that shouldn't be too much of an issue. I've changed engines before, but never swaped for a different one, so you can imagine I'm a little scared of messing it up. the 3:08 gears sound like a good way to start with this, and I was thinkin about putting electronic ignition in it too, so that will help too. Any excuse to put duals on it works for me! I may start collecting parts for an eventual change over, and when I do, oh boy, get ready for a barage of questions!
With a 60's Chevy truck bell you should be able to just about bolt in a V8, will have to move the mounts but I'm sure the frame has the holes already since they could come with a V8 if you wanted. GMCs did not come with a Pontiac (or Buick, or Olds) motor after the 305 V6 was introduced. The 305 is a stout little motor made to produce torque and would probably last forever if you maintained it, but doesn't rev very high and gets terrible fuel milage. In short, it's a good truck or tractor engine.
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