Radiator Support Questions

[Bill #34162]

Does the 70 small block rad support for aluminum rad have a part number stamped on it anywhere? I can't find one.

This same support has a detachable L shaped piece that attaches along the top, inside (towards the radiator) on the rad support and runs most of the way across the length of the support. It appears to me that this piece is what the top foam rubber seal should attach to. It attaches to the rad support with the same bolts that hold the top radiator hold down bracketclamp. Additionally, there are two holes drilled outboard of these two bolts where self tapping screw are used to hold the L shaped piece. My friends 69 (same engine, same aluminum rad) doesn't have this piece installed and doesn't have the outboard holes drilled for the self tapping screws even if it was there. Can anyone shed some light on which one, if either, are correct. Thanks as always.

[Joe L.]

Re: Radiator Support Questions

Bill-----

As far as I know, there is no GM part number stamped onto the 1970 radiator support or, for that matter, on any other radiator support. It would have been nice if GM stamped part numbers on all parts, but they didn't.

As far as the differences in the 1969 and 1970 small block with aluminum radiator support, there's a very good reason for that. Here's what the reason is: Early 1969 small blocks, from the start of production and until ABOUT August, 1969 used radiator support GM #3952900. This support did not have the upper seal adjusting panel which you described. Later 1969 Corvettes, from ABOUT August, 1969 used radiator support GM #3966591 which did have the panel. The GM #3966591 support then continued to be used throughout 1970-1972 PRODUCTION for small blocks with aluminum radiators (manual trans without A/C). I realize that this change is NOT shown in the 1969 AIM and is not shown in the 1968-69 Judging Manual (for which I share the blame), but that's the way it was. It just goes to demonstrate the limitations of the AIMs with respect to the copies which we all have.

Also, for others that may be interested or start figuring that the early 69 support was a carryover from 68, it was not. 1968 Corvette radiator supports are completely different than 69 and later.

[Bill#34162]

Thanks for the education. *NM*

[robert leazenby]

Re: Radiator Support Questions

you have helped me great deal in the past few weeks, so why stop now? I am attempting to replace my rediator support. All the vendors list two that are possible and I don't know which to order. I am away from home and can not go measure my car right now.

Anyway, I have a 70 small block, no ac, with a 4 speed, however it is an lt1, does that make a difference. I do not have an expansion tank, no holes on the inside skirt where one was ever attached.

Vendors show one for a 18" and one for a 26". I guess I could wait until I got home and measure but I wanted to get the thing on order.

Thanks in advace. On a side note, I would be absolutely lost with out this web site and everyone's help.

[Joe L.]

Re: Radiator Support Questions

robert-----

Actually, there were 3 different radiator supports used for 1970 Corvettes. However, one of these was for big blocks which used a radiator core which was 27" wide.

Small blocks used either a radiator with a 19" wide core or a 26" wide core, depending upon application. The key information in your post is that you have an LT-1 and that you don't have a radiator supply tank. That means that you require the core support set-up for the 26" wide core. Originally, this support was GM #3966594. The radiator originally used for your car was GM #3018803.