Inliners International Forums General Discussion Engines GMC 302 Verses Chevy 235 Distributors

I thought distributors for the GMC 270/302 and Chevy 235/261 engines were the same. I contacted a company that makes a mini HEI for the Chevy 235 and they said it would not fit my GMC 302. Can any one comment the distributor interchangeability between the late 1950's GMC and Chevy 6 cylinder engines?