Frame id

[mattfrediani]

Need help with Frame ID.

The only numbers I can find on my frame are on the outside rail of frame just opposite of the 2P205 case. I realize it may be a part number but it might help me figure it out. Theres no numbers above the steering box

3987550 220 3252

thanks in advanced
mATT

[B. W.]

It is a part #, my K20 has 3987549 220 12 15 52 stamped on the driver's side, the passenger side is one digit off (I think) so your 3987550 is in the passenger side I'm guessing? As far as the partial VIN near the steering gear box, from what I know, most Chevy trucks have them GMC's do not. Someone with more knowledge please correct me on this if I 'm wrong!

[LockDoc]

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Pictures are about the only way we can help identify it. '67-'68 frames are the same. '69-'72 frames are the same. The C20 frames are a little beefier and the rear cab mounts are different than the C10's. Pictures of the core support brackets and rear cab mount brackets would tell the story....

LockDoc

[57taskforce]

My 72 has a partial vin under the cab just behind the drivers side of the transfer case crossmemember as well as the steering box vin. Only problem is you aren't likely to find/read it with the cab on the truck. If it's a 205 and came that way from factory that would indicate a 69-72 frame. I would think even a gmc would have a partial vin by then. Seems like it was mostly 67-68 gmcs that didn't always have the vin. Post some pics up limesaid above. For 4x4 there's a few small changes in the frames year to year that can help identify them.

[mattfrediani]

My body is off of a 70 c20- my truck is a 4wd with a 350/350/205 Is it possible my truck was converted from a 2wd to a 4wd? It would be nice to know. Can the C20 frames be converted to 4x4? the cab vin says it was a manual tranny so my truck is a true frankenstein. The frame has the curved metal support brace between the core support and engine on the frame. its driving me nuts not knowing.
when I replaced my dana 44 & 60 diff covers i ran the numbers on the diff gears and they came up as 410"s out of a ford.

[B. W.]

Do a search on this forum on 4x4 frames & 2wd frames there are some distinguishable differences. If yours is a converted 2wd you should be able to see certain things that aren't the same as a 4wd. Parking brake cable location (2wd routed through the frame) bump stop pads brackets for the front axle on 4wd riveted in place. (converted 2wd, these may be missing) if the front axle spring hangers are riveted in place (vs bolted) it is a 4wd frame. (they could be bolted & still be a 4wd frame if someone took it apart to paint it which a lot of people do when they are restored)

The part numbers on your gears may be Ford (someone changed them) Ford, Dodge & GM all ran these axles. To ID you axles look for the BOM (Bill Of Materials) stamped on the axle tubes ( do a search on this also)