I have a 1976 W100 with a big block engine. This has got to be the worst truck to find parts for, and I have owned it for 12 years.

My newest battle is to find a new radiator for it but any pre-made radiators have the inlets on the wrong side. I was wondering if anyone on here has a big block W series and could tell me what side the top and bottom inlets are on.

 

Same as the the D-series, upper driver side for the inlet and lower pass for the outlet. They were all the same like that.

 

thanks for the reply, mine are switched, maybe this is the wrong radiator in my truck.

 

I have had good luck with one 800 radiator, I recently was forced to sell, my d100 clubcab 400 auto. long bed 1973. hold on... i just kicked myself again.
Keep it right side up. Chris

 

It does sound like the wrong one.

 

You did'nt say what big block you have. Could this be a transplant which was done B-4 you got it? The big block water pump housings do differ as to the lower hose position being right or left. They do however interchange and will fit "B" block 361, 383, 400 as well as "RB" block 413, 426, 440.
I have a 440 alum. housing on my 383 and had to have my radiator modified from left to right to use it. You should be able to get a raditor with the correct lower hose position, mine was new so I chose to have it changed.

 

That what I thought. Big Block water pumps have the lower hose tube coming out the drivers side.

This is the original 400 that my truck came with. The top doesn't matter too much but yes, the bottom inlet has to be on the drivers side. I bought a new radiator from Checker and I am going to have a radiator shop switch the bottom inlet location. It's that or buy some funky hose to make it all the way to the passenger side.