Good afternoon all,

I was hoping I could get some suggestions\guidance on a project I am thinking about.

I have a 1972 442 (factory 350cu). The car had a full frame-off (motor incl) 16 years ago (by my uncle), with 5,500 miles added since.
it had "upgrades" then:
High performance heads, (from a 2 to a) 4 bbl Rochester carb, bored.30, Crane Hydraulic Flat Tappet Cam, TH400 trans w\shift kit, 3.42 Posi rea.
I had a stall converter added when he gave me the car a few years ago as NO ONE could get the idle to run just right (tried the timing, adjusting the carb, trying different carbs..)



But now she runs great... Only PITA is that with this 3 speed trans, I can't go on long rides because with the RPMS running high on the highway, she runs hot....God forbid I get caught in bumper to bumper after driving hard (65+mph) for over 40 minutes. (I've had everything else checked, fan clutch, therm, all ok)



I was thinking off swapping in a 4 speed auto trans to reduce the rpms.
I also want to avoid as much "alterations" to the drive-shast, cutting, etc.
any suggestions on which trans i should purchase? or any pitfalls to look out for?


TRULY APPRECIATE ANY HELP OR DIRECTION..EVEN NAMES OF GOOD SHOPS IN NJ



(trying to avoid auxiliary fans since i think they are cheesey)



fyi: currently..at these steady speeds my rpms run:



60MPH= 2500 RPM
65MPH = 2750
70 3250
75 3500
80 3750

 

2500 RPM at 60 MPH is NOT high. Your overheating problem is something else. Fix that before spending money on a trans swap. The easiest OD trans swap is a built 200-4R, but expect to pay upwards of $2700 for a properly built trans. Again, this is not the cause of your overheating problem. These cars could run all day long at 70 MPH and then not overheat in traffic.

 

Aux fans won't help either, fans are not needed at speed. Your issue is either in your tune, timing or lean carb. Head gasket or clogged radiator.

 

I would suggest a 2 core aluminum with 1" or bigger cores in place of your current, I assume 3 core copper rad. As said 2500 rpm's isn't high but unless you are running a tall tire, it will be more like 3000 RPM at 60 mph. The 2004R bolts in place of the TH350, so at minimum you will need a yoke swap or a TH350 drive shaft from a 71 or 72 Cutlass. With a 25.6" tall tire, you will run at 1850 RPM at 60 mph with the converter locked up. As said, if you motor puts out over 400 ft/lbs, a $400 billet forward shaft and drum assembly plus many others mods will be needed to live. Here is a good calculator, it takes into account a lock up converter, otherwise add 250 to 300 RPM. It also has the 2004R .67 OD ratio built in. To find your current RPM, change to 1:1 ratio and add 300 RPM.
http://tech.oldsgmail.com/axle_RPM.php

 

I agree with the others.

I drive my car in 110+ summer temps, with the AC on, engine spinning 3000+ RPM on the highway and it doesn't overheat. I can't imagine that in New Jersey the ambient temps get anywhere close to what we get here. You should find out why your engine is running hot and address that instead of looking at a trans swap as that is merely a band-aid for the underlying issue.

 

OK, I'm now a little confused by the original post. Does the car overheat at freeway speeds or does the car overheat in traffic AFTER driving at freeway speeds? The potential causes are different (and none of them have to do with gear ratio).

 

It is a little vague on details. A new heavy duty clutch and a fan shroud should be used if it is running hot at low speeds. If it is highway speeds, I stand by my rad recommendation, something like the Champion 2 core with 1" tubes. https://shop.championcooling.com/Per...utlass-SKU-161
For the 2004R, contact CK Performance in New York. He is one of the leading specialists with the 2004R and part supplier, even to other known builder's. I would think his entry level trans will be more than capable, it is not listed and either his mid or high stall converter should work very well. He even shows modifying the early Qjet carbs to work with the TV cable, which is very critical to a 2004R trans living any amount of time. Also a large stacked plate trans cooler is necessary and I bypass the rad all together.
http://www.ckperformance.com/List/GM...missions/2004R

 

Hi Joe
I was on a 60 mile trip , in 80-85 degree weather...after 45 minutes at 75 mph the temp gauge grew hotter as expected, but all within a safe temp zone ( but then when I hit bumper traffic, the needle goes up fast and the red Warning light starts blinking. I wasn't held up long and got back up to 50 mph which brought it down a bit . I then arrived at destination 15 minutes later(temp gun i carry showed hottest point at therm housing at 240 degrees) Let her cool a few hours. Return trip was done in cooler temp, no warning lights.
I have an aftermarket radiator that's rated = to or higher than OE for all 1972 442 engines. Model radiator # 433161 (1 row\1" tube \aluminum \ trans cooler)

 

What fan set up is on it? Does it have a shroud? Are all the factory air dams in place? While that rad won't be a good as a 2 core aluminum rad, it should cool a 350 just fine. I have a recored copper/brass factory 2 core with the factory 4 blade fixed fan and no shroud. I have never gone over 200 sitting in traffic.

 

This factory 350 was upgraded to give the HP of the 455:

Bored .030, crank cut,rod journals at .020, main journals at .010, forged pistons High Volume oil pump, Crane cam
balanced, block & exhaust manifold resurfaced 3.42 Gears \ TH400 Trans w\ shift kit \ 4-bbl Rochester true dual exhaust. TH350 to TH 400 trans
so to keep it cool, the HD (6 blade) fan\clutch was added. full shroud. 160 degree therm.
So, maybe I'll start with a 2 core rad before I mess with the trans upgrade.
Any specific brand you can recommend ?

 

The Champion 2 core with 1" tubes, fit and cool well at a good price.

https://shop.championcooling.com/Per...utlass-SKU-161

 

thanks!!