The Stovebolt Site Forums The Shop Area Driveline sm420 gold mine

Recently discovered my sm420 was not original to my '54 3100. (due to the weep hole in the front bearing retainer).

I read somewhere about some guy that has 100's of 420's. I really want to find a 420 from a '54 so my truck will be "numbers matching" and have the "upgrade" of the seal up front.

anybody know where this guy is or anything that might help.

Thanks a bunch guys!

-LGringo

An upgrade is available from these guys. http://www.novak-adapt.com/catalog/sm420_parts.htm However, the seal in front is a much later upgrade that is mainly for rock crawlers. How do you know the transmission is not original. Having a weep hole sounds original to me.

Numbers matching kind of urks me. The transmission is the same from 48-67 with a few minor changes. If you have an open drive 54, you could use transmissions from 54-67. Trying to cherry pic one for the correct year seems a little crazy. The factory would have used an engine and transmission combo that were less than 1 month apart in production. Why not go the whole way and get a transmission that was produced the same month as your engine?
John

In a 1/2 ton it'll be low enough to the ground on one is going to crawl under it at a show and nit pick....
Run whatever year you find.

Or, if you are set on finding the proper year transmission I then also hope you are as careful and exact on every and all the other details, making it as close to original as humanly possible.

Grigg

I kinda came to this conclusion last night. The plan was to make it very original. But after watching the same truck sell on Barret-Jackson for only 28,000 and restored to near perfect originality my goals changed.

By no means do I intend on selling this truck any time soon, but many years from now I want to do a '54 or so GMC and then this truck could maybe be sold. So I figured why kill the fun of restoring the truck with nit-picking details.

Now I am still gunna pay attention to details but I think this tranny will do for my needs. I am only 19, so this is the first of MANY builds (really 2nd build, 1st resto), so this is just a "learning" project.


As for knowing tranny is not original:
1. tranny was made in early '53
2. '54 does not have the weep hole
3. shifter was bent multiple times to "follow" the curves of the dash
4. tranny cover on the floor was butchered to accept the shifter.


thanks for help !
-LGringo

This is most likely the truck you are referring to?

It is a beautiful truck that looks to have had excellent work done on it. However, it has be not been restored to "near perfect originality".

I have almost never heard of anyone who did a "stock" restoration (or a resto-mod restoration, for that matter) ever sell their truck at a profit (especially if the included their time at $5.00 per hour).

Tim, I figure my work at -0- per hour and the only vehicle I own that I could sell and make a profit is a 56 Ford that is the most original vehicle I have ever seen. It ran poorly and I put on a correct NOS carburetor and it now runs like new. JC Taylor suggested I insure it for 3 times what I paid for it. If I were to do some work on it, it would be money in a black hole. Anyone who think s we are in this hobby to make money is in for a rude awakening. I think "numbers matching" is a stage a lot of people go through. Most outgrow this stage.

I recall when my dad had finished rebuilding trucks for himself, my brothers and me, he thought he could start rebuilding some with updated mods (brakes, 12V, etc.) to sell. After the first one he gave up since he couldn't even get what he had for parts into it...

Ha, ya, I think I out grew it and I aint even done with my first build.

Although, I think there is something to be said for a numbers matching resto. Its a lot of work if the vehicle is not original from the start. Not that I'm scarred of a lot of work, just unnecessary for my build, as yall (and myself) have convenced me.

-LGringo

There is no such thing as "numbers matching", as is commonly referred to, on these trucks, due to the wide range of years, their parts interchanged. Unlike the vintage classic Corvettes, Chevelles, Mustangs, Cobras, and the various MOPAR offerings.

It is possible to pull a casting number from any part, that has a readable casting number on it, from one of these trucks ('46-'72) and discover that said part was available, as standard equipment, on several years & models. The truck could have a part on it, that was produced & installed 10 years after the truck rolled of the production line.

Conceptually speaking, numbers matching, is determined when the VIN tag or other criteria connected to the vehicle, identifies the equipment the vehicle was equipped with, at the time of production. As with the Chevy trucks of this era, the VIN or GVW tags, did not identify the R.P.O.'s of the vehicle, therefore it is virtually impossible to determine what equipment was on the vehicle without some supplemental documentation, like an SPID label, original build sheet, dealer invoice or customer order form.

Here is an excerpt from an informative site, regarding the cliche "numbers matching":

Depending on whom you talk to, the definition of a “matching numbers” car may vary. A classic car purist might say that a truly original, matching numbers car will still have all the parts that it was manufactured with, including the tiniest nut and bolt. That would be very hard to find in an older car, so a more practical definition might be that all the parts will be either from the assembly line at the time of production or have been replaced with authentic NOS (new old stock) parts.

The most general use of the term “matching numbers” would mean that the engine and transmission are marked with the same sequence number as the chassis VIN number, and the rear axle/differential’s date code and casting number corresponds with the vehicle that's being checked.

Numbers matching

My "other" hobby is gunsmithing, and collecting antique firearms. A "numbers matching" 98 Mauser rifle with all original parts, including the correct proofmarks and inspector's stamps, in excellent condition, would sell for several thousand dollars. The same rifle, with a "period-correct" stock, bolt, or magazine box from another rifle might be worth less than half. A cobbled-up rifle assembled from original, but mismatched parts might go for a couple of hundred dollars. Same parts, same ability to drop a deer in its tracks, but extremely different dollar value! The average military surplus rifle has about 30 parts, not the thousand or more a vintage vehicle has! It's a lot easier to collect "numbers-matching" guns than trucks.
Jerry

enjoy your truck, enjoy the search for your parts and best of luck when you find them. I kinda like the small details stuff.