I am doing a 4.0 swap on my 88YJ and need a new radiator. Should I get one for my '88 year or one for a '92 & newer 4.0 YJ? Anybody know the differences? Radiatorbarn.com shows very slight differences but overall seem the same.

I don't know what differences there are, if any, but I swapped in a '98 4.0 in my '88 YJ and have been using the stock '88 radiator for 2 years now with absolutely no problems. If I recall correctly the hoses will match up exactly.