rear coolant crossover on SB?

[PanGasket]

There any benefit at all to this or is it just a precaution? It can't be too important since the factory blocks em off on 340s and most aftermarket aluminum intakes do too, I know my Air Gap does.

 

[replicaracer43]

I think some of the last TBI 360s had that passage in the rear tied together, and had a passage in the bottom of the intake to tie it into the thermostat housing area. I plumb external water lines from the rear and to the water outlet on my circle track motors. The main advantage is keeping the temp even across the head, water coming out of both ends helps.

 

[blue missile]

43, The manifolds that have that crossover at the back also had a tap so you could send water to the front.
I converted my LD340 a while back, and I will do the same for the new motor.
Your statement is quite correct, I dont understand why this is not done more often.
Andrew