Single or dual pass radiator

[BBC71Nova]

Getting ready to order up a radiator soon. Should I go single or double pass? This will be a big block combo with manual trans and A/C.

Initially I was thinking double pass in case I decide later to go LS power. The outlet sizes are different though. Now I'm thinking if I do swap later a new radiator will just have to be figured into the cost.

Thanks!

[IMPALA MAN]

Go double pass. Here is why. The way many LS hoses run, a radiator with the inlet and outlet on the same side, works out perfect. So here is the summary:
If you stick with te BBC, you'll just have better cooling. If and when you switch over to the LS, no need for a new rad. I know AFCO offers direct bolt in units for LS conversions.
Also look for a "real" double pass. You want to make sure the plate that divides the top of the tank from the bottom is welded all the way around. If not, water will just run down to the bottom of the tank and the radiator will not cool even as good as a single pass. Believe me, there are rads out there being built this way. I ran across one on a freinds car.
Best of luck.

[WSSix]

That's not a bad suggestion. If, however, you decide to go single pass, you can always just change the inlet/oulet instead of replacing the whole radiator again. The LSx does not need a double pass. It just needs smaller inlet/outlet. I want to say the diameter is 1-5/16" but I'm not 100% on that.

[IMPALA MAN]

Another option would be to have female AN fittings put in the rad for the inlet and outlet. Then you can use the threaded adapters that thread into the bungs and have a barb on the other side to slip your hose on to. Then the sizes can be changed within a minute or two.

[BBC71Nova]

Thanks guys. The AN idea seemed pretty cool and not something I really considered yet. Then I priced the fittings :wow: . You can almost buy another radiator for what you'd spend on fittings for the AN route.

I went ahead and just ordered the single pass. If it weren't for the different size hoses I'd have probably went dual pass.

[badmatt]

If its in your budget do a dual pass 1.25" core.