I am working to get my 1973 club cab truck back on the road with a 4bt cummins diesel and 47RH over drive trans.

It is a factory A/C model, but the system is incomplete and has been open for decades.

I have a 2000 parts truck and was wondering if anyone has done any swapping of a complete newer system under dash blower box, etc into an older truck. I know it will take some fitting, but in the end might come out better/cheaper than repairing the old stuff.

Anyone have experience with such a swap even on a different model or car? Mostly curious about switches and the electrical part of it. With enough cutting I know I can make it fit.

I think it might be tough to do, the boxes are totally different. The newer box would most likely be vacuum operated so you would need all that stuff if you pull the box out of the newer truck.

All of the plenums and ducts would be tough to retrofit into the older truck, not sure how you would accomplish that without supreme fab skills or a lot of half-baked cobbling. The electronics would also be a pain to figure out.

I'd keep the old box in there and get it working properly. Not sure if they are available for trucks but I know there are seal kits to refurbish most cars. Tons of stuff on Ebay - takes time to search for it but it's usually your best bet for the right parts.

The stuff in the engine compartment might work since they are mostly just mechanical though there is a low pressure transducer on newer trucks, can't recall whether it goes into the PCM or not. Newer Sanden-type compressors are swapped in all the time, you just need a bracket to mount to your your engine.

Bouchillon has a bunch of stuff to do this type of thing, maybe give them a call and see if they can steer you in the right direction.

http://www.bouchillonperformance.com/ac_condenser_kits

http://www.bouchillonperformance.com/ac_switches

when putting a 6bt into a 69 gmc truck you only need to have the provision for an orifice tube to mate the new cummins stuff to the old truck stuff---i would talk to one of the AC guys at tubes and hoses---i had such a project going and was about to get the hoses mated together when i got mowed down by a crazy driver----on the hole in the firewall for the plenum they are different and will take some work....

As mentioned by RAMCHARGR, I think it is easiest and best to re-use the in cab part you have and adapt it to the compressor on the 4B. The evaporator coil inside would need checked and is likely OK. With the appropriate expansion valve and freeze switch, it can be adapted to the compressor on the 4B... or a Sanden replacement.

Classic Auto Air in Florida can recondition the in cab part or DIY. Bouchillon is a great source as well.

There are lots of bracket kits to mount the newer Sanden compressor on the 4BT, flush the dash box and complete the system with a combo of new hoses and replacement factory parts.

Sounds like the best idea up dating under the hood and keeping the inside as it is would be the best route. I know the a/c system in the truck melted a fuse sometime in the late 70s and wasn't used since, nor the heater. But I was planning on doing a new fuse panel and some rewiring anyway. I will look into the blower box and see what shape its in. I have a factory a/c 1975 parts truck as well so I should be able to at least have all the parts even if they need fixing.

If you're not redoing the original system, then my advice would be go totally new from Vintage Air. I know I can only stand so many hours of standing on my head in the cab before I get totally bent out of shape, physically and mentally. The VA kits are industry leaders.

But, redoing the original is probably more cost effective and should produce a good result.

R.