I ordered a new Dewitts Black Ice "Direct FIT" radiator for the 82.  I got the old radiator out with no problems but the new radiator is thicker.  As others have experienced, I cannot get the new radiator installed with the Fan Shroud in place.  When I tried, I ended up marking the front of the radiator (will try to straighten fins with a pic).  

Not sure if all C3's have the same "V" shape in the center of the upper radiator mount, but for mine, this is the JAM point.

I removed the fan, but the shroud still won't pull back far enough for the wider radiator.  

The bolt on the upper control arm on the Driver side prevents getting the needed clearance.

I dont see how removing the hood helps in my case.

Has anyone tried removing the radiator support frame?  the 82 is held in place with 3 screws on each side but the bottom screw will need the front air dam removed.  My thought was if I could tilt the frame I may get enough clearance.  I was going to drop the radiator frame completely but then realized I had to disconnect the AC condenser but that would just create other problems.

Has anyone managed to get one of these wider radiators installed in the late model C3's and if so, how?

Never tried replacing the rad on an '82, but I HAVE had to remove the upper control arm bushing bolt on several over the years to be able to get the shroud off, or moved enough to remove the rad. Don't know if that helps, but....

And no...not all years had that "V" shape in the center of that area.....that's all you bud! Clearance for the fresh air door solenoid...'82 only. 

What about removing the top 2 screws on each side and just loosen the bottom screws to rotate the core support forward a little?

My DeWitts dropped right in.  I did have to replace the core support, but that went in first.

Thanks guys, Think I will start with removing the control arm bolt.  Given the "V" shape of the upper radiator support I may also need to tilt the entire support but that is a bigger job, so start with the bolt.  would have been much easier if they designed the radiator support with couple bolts holding the upper support bar in place, but as I learned long ago, cars were never designed with "ease of repair"  

I installed a DeWitt Radiator in my 1974 Vette because of the cost of rebuilding the original.

I needed to move the core support forward to remove and replace the radiator. There was no other way to work it and the easiest solution.

Finally got the radiator installed.  My son the mechanic had a look, we ended up removing the fan from the water pump (4 bolts) and the pully.  That gave us enough room to pull the fan shroud back/up slightly.  This gave us enough room to slide the wider DeWitts radiator in place.  We still had to install by first rotating the radiator about 45 degrees so we were lowering it in place with the "Right Lower Corner" first (where the lower radiator hose connects).  This allowed the lower radiator hose connector to fit inside the fan shroud then we could rotate the radiator back to level and work that lower radiator hose connector back out of the fan shroud and slide radiator into position (all this was to get around the upper control arm bolts).

Thought we had it -- NOPE , not my luck.  Turns out the new rubber radiator mounts Zip corvette sent me would not work.  These DeWitts radiators have wider/stronger weld joints along the seams.  These prevented the radiator from seating into the upper/lower mounts.  I called DeWitts and talked with a tech.  They sell their own version of rubber mounts designed to fit their radiators, however, the radiators they sell through ZIP Corvette have a slightly different design.  The ZIP radiator version has a flat top where as the version DeWitts sells from their website has a raised center channel.  The tech said I just needed to cut a small part of the upper mounts rubber to remove the excess for the raised center channel.    

After the slight modification, the upper mounting brackets bolt holes aligned with a little downward pressure.  

Now I just need to tighten the transmission cooler lines (the 82 build manual says torque to 34 nm, but I dont think I want to attempt that much torque.  I'm thinking finger tight and one more turn or until the metal connector stops wiggling), refill the tranny and radiator.

Glad you got it in but why didn't you just buy it from DeWitts?

Yeesh! I thought you had already removed the fan! Guess I coulda axed....but ya...makes moving the shroud MUCH easier. Glad youse guys got it figured out, anyway. 🤠

I've had the raditater out of my '74 several times over the years....never had to move the core support...just the shroud, after removing the front, upper control arm bushing bolt. With that bolt out(and the fan/clutch), the shroud will come out.

The Corvette Gods are mad at me, don't know why.  The 3/8 hose worked perfect - Thanks so much for the suggestion (I was too fixated on the 5/16 in the Build manual).  Put new hose clamps on and torqued to spec.  Ran the car on the hoist to get tranny oil up to temp and topped up.  As I looked at the upper radiator Transmission connection, it looked like fluid was seeping out the hose.  I got under car to inspect all my lines/connections and all 4 connections were dry.  The tranny fluid was seeping out of the upper radiator pipe connector.  

Here is where the Gods got angry.  The 12 mm spanner was hair too small and 13mm too large, used half inch spanner (which I used to tighten with) and it rounded the nut trying to loosen off.  Will have to order another "Pipe Assembly" from Zip or Summit (none of the local auto parts stores sell this) AND HOPE THE THREADS INTO THE RADIATOR ARE STILL GOOD.

Next week's challenge.  Tomorrow is set aside to replace AC Dryer, fix a connector leak and re-charge.

Metric spanners?  Do you have any SAE (inches) wrenches?  When did GM go to metric?