Rob, I don't know of any radiators that are a bolt-in and even if there were one that would fit, it wouldn't have any more cooling capacity than the stock one for its size. Here's some food for thought, although it does not qualify as a no-headache project......This is copied from a wiki article that I contributed to.....
Swapping a core support and matching radiator into a recipient vehicle.
In doing this swap, you will have to re-install the recipient vehicle's hood latch onto the donor core support in the proper location. Make up a fixture beforehand from scrap metal that bolts to the fender bolts or some other location that will be the same after the core support swap, and will show the proper location for the latch. This is a must-do when doing a frame or clip swap.
Recommended donor vehicles.
'76 Cadillac Fleetwood or Eldorado. For example: 1976 Cadillac Fleetwood 8.2 liter V8 radiator.
Mid-70's Chevrolet truck with a 454. For example: 1975 Chevrolet C20 Pickup - 7.4 liter V8 radiator, 4-row capacity upgrade (and, same radiator in aluminum: here).
[edit] Cadillac radiator swap
Any of the Fleetwoods or Eldorados from '70 to '76 with a 472 or 500 will work, but the '76's used the 500 inch motor for sure.
Call around and find a boneyard that still has the fan, shroud and core support. You'll be using a new radiator and viscous drive fan clutch to bulletproof your installation. Make yourself a memo of the exact year and model the pieces came from so you can match up the parts.
You may or may not have to alter the fan clutch hub where it bolts to the water pump/pulley. Usually, the holes are slotted so you can make it work. If not, some minor surgery on the hub with a rat-tail file will do the trick. With the motor in the vehicle and finalized for position, bolt the fan clutch and fan to the water pump. Mount the Cadillac radiator and shroud to the Cadillac core support.
The Cadillac core support will probably be longer side to side than the stock one in the recipient vehicle. Retain the outer pieces of the recipient vehicle support where it bolts into the body and cut the middle part of the recipient vehicle support out with a reciprocating saw, leaving a few inches on each side. Then, measure the opening between the two stubs that are still bolted to the recipient vehicle and cut the Cadillac support to fit into this opening. It's better to leave a little more sheet metal on the Cadillac support until you determine the correct position of the fan where it engages the shroud opening. Then, position the Cadillac support with radiator and shroud attached up to the fan, equalizing the distance between the fan blade tips and the inner circumference of the shroud all around. Move the shroud around the fan until you have the fan blades halfway in and halfway out of the shroud opening. Normally, you'll have to tilt the top of the radiator/shroud back a little at the top to match the fan angle because the motor sits in the recipient vehicle on a rearward tilt. If you need a little more front to rear clearance for mounting the support, you can position the fan blades 2/3 in and 1/3 out of the shroud opening. A little further in is OK, as long as the fan clutch is at least 1" from the radiator core material. A little further out is not OK.
With that accomplished, simply attach the middle piece of the Cadillac support to the stubs of the recipient vehicle support. Use whatever pieces of sheet metal or whatever that you have to in order to make the connection. The Cadillac support may end up sitting forward of the stubs or a little behind them or it might fall exactly into place and you'll have very little welding to do to stitch the Cad support and the stubs together. Whatever. Just use your head and figure out how to connect the sheet metal, then MIG it in place.
Now, you will have a radiator that will cool anything and you still have the stock attachment of the stubs to the recipient vehicle so you can use simple hand tools to disassemble the whole mess later if you have to. It'll all come out as one piece -- because it is one piece.
