FRANK BASILE wrote:Thanks Bob. You mention "drilling the steam holes" . This applies to 400 heads being used on the 350 block? . We got told that one could not use 350 heads on a 400 block. But the other way around was okay. We did end up just replacing the 400 block with a 350 and using the heads that were on the original stuffed 400 block. The other difference from memory was the balancer, something to do with 400 crank and balancer being a matched pair ? . Long time ago now.
Frank the 350 heads would have to be drilled for the steam hole between the centre cylinders to use them on a 400. Not sure why they wouldn't work the other way around. The 400's are externally balanced so you need to use the 400 drive plate and balancer unless you can get the crank internally balanced. Not sure if there are any problems doing this or not