The Stovebolt Site Forums The Shop Area Engine Shop What Engine and Drive train to use

I have just purchased a 51 GMC pickup. I know nothing about American trucks being a transplant from the UK.I intend to rebuild the truck to look standard but will want to use it as my day to day transport, I don't know what engine and trans I have. I need to know what to use, keeping the in line six and stick shift driveline, but with more power and driveability. Anyone please help.

Hi Welch 63, Welcome to the Stovebolt Page.

For starters, read the number from the shelf on the engine block to the left of the distributor. Most likely it will start with 228. If so, you have a 228 GMC engine.

You don't mention whether you truck is a 1/2 or 3/4 ton truck. Does it have any markings on the hood ? A 100 emblem would be the mark of a 1/2, a 150 denotes 3/4 ton.. If you are thinking about changing the rear gears to a higher ratio, your choices depend on whether it is a 1/2 or a 3/4 ton vehicle.

You said it has a stick on the floor , it is probably a 4 speed transmission..

Give us a little more information and I am sure a few guys will jump in with some ideas..

Ok Bill the number on the plate to the left of the distributor is 270857801, it has a four speed on the floor, there is no numbers on the hood, can you help me any more please. Jason

Welsh63, you have a 270 there! Congrats! Your 4 speed is an SM-420 made by Muncie. They were used up to '67 models, then as they "homogenized" the GMC trucks, they went to SM-465's and NP-435's.

Howdy, and welcome! Sounds like it's time for the vin#, or ezer yet, how many lugs on the wheels? Do you want to mess with the engine a little? The jimmy will like headers, and you're from th UK right? how about 3 SU carbs? ez to do on these inlines. Rear end gears are a definate and maybe a T-5 if you really want to cruise. Is that enough ideas? Took about 3 lines to say it, it'll take a little longer to get it done but very cool .

Well this is just great, thanks everyone for the great welcome, the serial no: 102 22 5 7835, just got in to late and dark to check lug pattern. yes I will want to improve the engine's breathing habits. I am a Brit but I now live in Texas.
Thanks once again to you all

That serial # identifies a longbed 1/2 ton, a good find. If that's an "S" rather than a 5 in the 6th position, it denote St Louis assembly plant. The rest is the sequence number.

This may sound simplisitic but being a relative novice I can say that after what I have learned from some of the real experts that post to this web site I have learned the most from reading catalogs ... catalogs tell you the time, with a short description of how the clock works. Reading catalogs, and reading this web site, starts to make sense after a while. For instance, the Classic Performance Catalog is broken up into sections by model series, starting with 47-54 Chevy AD trucks. They show you suspension, brake, spring, shock, sterring column, power steering column, rear end, trans and engine mount, sheet metal, gas tank, and radiator upgrades with a breif description of what is is and why you might want to use it... on the page for engine & trans mount there is a breif description of how to set the rear pinion angle. Just enough info to explain why, how, and help you decide if it's something you want to do yourself.. I've got a stack of catalogs, this is just one example. Speaking as a novice I suggest a lot of reading early on and it starts to make sense. Hope this helps.