I am dropping a small block v8 into a toyota 4runner. I have done toyota v8 swaps before and have usually had cooling problems. It is a small engine compartment and not room for a large radiator.

I want to run something unusual like a 406 (400 block 350 rods) or maybe an everyday 383. I have heard the 383s run hotter than normal. Should I just stay with the 350?

Appreciate your input.

There are a ton of factors that will determine the heat but I would say that the 350, then 383, then 400 in order from coolest to hottest.

The rule is: more hp = more heat. In practice, engine tune (timing and air/fuel ratio) make more difference than the amount of hp you are running. If you have a big enough radiator, and enough air moving through it, any engine will run at the temp dictated by the thermostat.

How much horsepower can a 22"x19" griffin aluminum raiator cool? Using a electric fan. I have one in a toyota with 350hp 350 and it stayed cool but this one will be pushing a little more power.

A 383 made with a 350 block will run cooler than one made with a 400 block because the 400 block has siamesed bores with no water flowing between the piston bores.

In any case, no matter how hot it runs, if you get a GOOD radiator you won't have a problem, even in death valley.

Spend the money and do it right.
Besides, you can get a universal summit aluminum radiator that's just like the griffins or be cools excpet you have to fabricate brackets.

dude a 406 isent a 400 with 350 rods (5.7) iits a stock .30 over 400 with 6 inchers or at least thats thay i remember it. would like to now for sure thoe

A 406 is indeed a 30 over 400 but they make a kit that uses 350 rods and special pistons in the 400 block. It is the same displacment but longer rod ratio. Someone correct me if I am wrong.