I've always wanted to take two heads from an appropriately sized and spaced v-8, lop off one cylinder and then weld the two 3-cylinder heads together and mount them on a 261 with the intake on one side and exhaust on the other.

I read somewhere that someone did that and it worked well, but I haven't been able to find the article since I first saw it.

'51 Chevy 1/2 ton w/'62 261, HEI, offy, fentons, dual carter/webbers, t-5 & 12 bolt posi