Is it the original engine?

[Trip59]

How do you tell? I just bought a 72 GMC, the owner said it WAS a standard, now has a TH350 and a tilt automatic column (in my list of things to replace) but I don't know about the motor. The emissions sticker on the fender well lists a 307 with 2bbl carb, from looking at the motor, the exhaust looks appropriate (from memory) and it does have a 2bbl carb. The number off the pass. side pad has a TDA suffix, which is either a 72 307 or an 80 350.

What other numbers do I need and where can I find them, or can I ever really tell if it's the original motor?

It's a half ton with leaf springs in the rear, discs in the front, listed 307 motor, what tranny would it have had (so I may start hunting). Looks to have a low tunnel cab, and was column shift, does that limit it to a 3 speed?

I was also wondering about how to tell what the rear end was, guess I might as well lump that into this post.

If this belongs elsewhere, please accept a n00b's apologies.

Trip

[yote1234]

tda=1972 307.. looks right..

[ready2go69]

TDA 1972 307 C-10 & 20
TDA 1980 350 C-10 & 15
TDB 1972 307 C-10 & 20

Partial Serial # will be on front pad I think.


Good information at
http://www.nastyz28.com/chevy-engine-code-stampings.php

[Trip59]

Thanks! I can't figure out the rest



Is there more to it, to find out if it's the original, or just a similar displacement? I'm going to try to get the #'s off the back later, I'm at work and not able to get dirtier than it takes to wipe that front pad...

[rsavage]

The V stands for Flint Engine Plant. First 2 numbers month, second 2 numbers day (Nov 15th) TDA is one of the engines put in trucks 71-72. Look on the back of the motor on drivers's side just beyond the back of the head. There is a block casting number. I believe a 307 for 68-73 should be a 391436 casting number.

[Trip59]

Cool! the different characters 2, 3, 4 had me scratching my head, they don't look like all 1's.

Anyhow, I just got back from chatting with the guy I got it from. Original everything on the truck, 307 for sure. New carb, but a stock replacement. Has a 350 trans in it, BUT I also just scored a complete, ready to go, rebuilt Saginaw 4 speed with a hurst competition shifter. From what I remember, should swap straight out for the 350? Fresh machined surface, brand new disk and bearing, quality rebuild with good fluid, shifter feels nice and tight (will have to make a new lever though).

Also scored some parts, but I'll wait to post spares and swaps until I pay up my membership this weekend.

Trip

[GASoline71]

A lot of TH350's were put in 1972 trucks. I have the exact same truck with the exception that I have a 350 c.i. engine too.

Turbo Hydramatic 350's are excellent transmissions, and can be made to take a lot of horsepower. My truck is pushing over 400hp and my TH 350 was built to handle it.

If the bellhousing for your 4-speed is for a small or big block Chevy... it will bolt to the back of the block. Is it a car or truck 4 speed?

Gary

[Trip59]

The one in there now is a recent replacement for the previous replacement of a TH350, and is chugging fluid and I had planned to replace it with yet another TH350. Long story short, I prefer manual. I just picked up a box with the clutch and brake and some bits and pieces needed from another board member with the intent of finding a manual eventually.

The one he has, he has no plans to do anytime soon, but purchased to go behind a '73 307 in his '58 Impala. So... I figure should fit nicely behind MY 307, which, even when rebuilt, will only be stock power and never really tow much or haul a big load.

It even has a rear yoke sitting on it. Only thing I need it an arm and it's ready to bolt in. Well, that and to make a custom lever, only has a short one and I'm too cheap to buy the one for a pickup with a bench.

I remember having to buy a cross member when I took the 3 speed out of my '68 and put in a TH350 behind a 350 (it started with a 250) but he's telling me that the Saginaw 4 speed is the same length, mount, etc. as a TH350. Yes?

Trip