Stock brass radiator in '69 350/350?

[G B.]

I saw a '69 350/350 4-speed convertible today that had a stock-type GM brass radiator rather than the usual aluminum set-up. This car wasn't air conditioned, and I don't believe it had ever been a big block. The 350 engine and Muncie appeared to be assembly line parts. The brass radiator was mounted in a GM core support with full shrouding and seals. It was a dead ringer for an a/c car radiator configuration.

Is there an explanation other than an owner installation? I thought that '69 small block non-a/c cars all came with aluminum radiators from the factory, but maybe I'm misinformed.

[Tom B.]

Re: Stock brass radiator in '69 350/350?

Jerry,

Your guess is probably as good as mine. The 68-69 JM for the 350/350 version of the small block shows the brass radiatior was used if equipped with A/C or automatic transmission. It could be as you mentioned, "owner inspired", or it could be an indication that the A/C was removed or the automatic transmission was replaced with a 4-speed. I haven't, but maybe others have heard of similar 1968-69 examples like this that came with a brass radiator from the factory. TBarr #24014

[Roberto L.]

Re: Stock brass radiator in '69 350/350?

I have information about 69 L46 cars with that components having two posible configurations for unknown reason/deviation. Normal with Al. rad 3155316 and exp tank and some cars with brass radiator, without expansion tank. Joe explained it sometime ago in another post. So this car could be original in those components.

Roberto, NCRS #30019, RMC

[Bill Clupper]

Re: Stock brass radiator in '69 350/350?

I owned a late '68 327/350 all original car, with brass radiator setup.

It surprised me at the time, but it was a 35000 mile car with no evidence of having been changed. There is quite a bit of difference, in addition to the surge tank in bracketing, shroud, and some other things I can't remember.

[Gary F. LeDuc]

Re: Stock brass radiator in '69 350/350?

This is a factory configuration - I also have the 350/brass radiator combination. The next judging manaul revision will even cover the configuration. Not sure, but I think they were more prevelent in the later production cars.

[Terry M.]

Re: Stock brass radiator in '69 350/350?

It may or may not relate to 1969 situation, but all 1970 350/350 L46 had copper radiator. In 1970 only base 4-speed got aluminum radiator. Any upgrade in engine, transmission or C60 got copper radiator.

Terry

[Joe L.]

Re: Stock brass radiator in '69 350/350?

Jerry-----

I agree with all of the other responders; I've said for a long time that I believed that some 1969 L-46-optioned cars were built with brass radiators. For quite awhile, Corvette afficionados looked at me with a "jaundiced eye" when I made that claim, though.

It is very easy to tell if a 69 big block was converted to a small block with the radiator configuration remaining the same. Usually, of course, the swap goes in the "other direction" but, the radiator used on all 69 big blocks was equipped with an external supply tank(both brass radiator and L-88 aluminum). The brass radiator used on any small block so-equipped did not use an external supply tank.

For 1969 L-46-optioned cars equipped with the brass radiator, I believe that the radiator originally used was GM #3018803. This is a brass radiator WITHOUT oil cooler fittings for automatic transmissions. It was also used on all 1969 small with manual trans and A/C. This is a fairly uncommon radiator. It was discontinued from SERVICE in late 1974 and replaced by GM #3018802. This is the original radiator used on 69-72 small blocks with automatic transmissions, with or without A/C. This radiator has, of course, the auto trans oil cooler provisions. In SERVICE for non-automatic-equipped cars, the oil cooler fittings are plugged. It is also POSSIBLE, but I consider it HIGHLY UNLIKELY that the GM #3018802 radiator was originally used on 1969 L-46-optioned cars. Certainly, no L-46 was built with an auto trans, so the oil cooler provisions would have been unnecessary, and the GM #3018803 radiator without oil cooler provisions was available.

In any event, if one finds a 1969 L-46 with the GM #3018803 radiator, it almost HAS TO BE ORIGINAL. With the GM #3018802 radiator it's also highly likely that it's original, too, but may or may not have a replacement radiator. With any other radiator, who knows?

[Tom B.]

Re: Opinions: Will temps for these run hotter?

Just curious about this, especially with the C3 body. Several years ago when I bought a 66 L79 327/350 it had a replacement brass radiator and the temps ran around 220. When I replaced the brass with a reproduction aluminum radiator, it ran cooler, somewhere under 210. I already know how a 68 427/435 runs hot. And I don't mean to imply "over-heat" but do these small block C3's with the brass radiators run hotter than it would with aluminum? TBarr #24014

[G B.]

Size matters

Tom -

The brass radiator in this car was huge and appeared to have 3 or 4 rows in the core. It was a GM radiator that still had the two letter identification tag, but I didn't see a 7 digit part number. There were no fittings for automatic transmission lines.

I drove the car on an 80 degree day. The engine temperature never budged off what I figured was 180 on the gauge.

[Joe L.]

Re: Size matters

Jerry-----

I don't know what the two alpha-character broadcast code is for the 3018803 radiator, but the core should be 26" wide, there should be no trans oil cooler lines(as you've apparently already determined), and the radiator cap should be on the right side tank. If this description matches the radiator and the radiator is a Harrison, it almost has to be the 3018803.

[Joe L.]

Re: Opinions: Will temps for these run hotter?

Tom----

As Jerry mentioned, this is a very large brass radiator; I would expect cooling to be excellent. Most big blocks used a brass radiator of a size similar to the 3018802/3018803 small block radiator.

Brass REPLACEMENTS for the aluminum radiators are another matter, altogether. When a brass radiator is manufactured with a configuration necessarily the same as the aluminum unit(i.e. so it will be a direct-fit replacement for the aluminum unit) it usually will not cool anywhere near as well as the unit it replaced.

[Terry M.]

Re: 3018803 code3 MK??

Joe & Jerry,

I think the code for the 3018803 is MK, but I am working off of 20 years ago memory so don't shoot me if I am wrong. I looked quickly where I thought I had that reference and it turned out to be codes for more recent part numbers.

Terry

[Joe L.]

Re: 3018803 code3 MK??

Terry----

Code "MK" was, for sure, used for the 1976-1978 radiator GM #3035558. It's also possible, of course, that it was used for the earlier 3018803, too.

[jon herrick]

Re: Stock brass radiator in '69 350/350?

I have an original 69 350/350 conv. that does not have a aluminum radiator or surge tank. It has never been touched. I have seen it both ways. Also my car has a 3 pin hood blanket and air dam seals on the shroud.There were many variations in 69 and I have witnessed a variety of differnt combos on 350 cars. Jon