Same Transmissions? 1965 GMC and the Chevy truck of the same year?

[mookiex4]

I am about ready to drop a 1967 327 V8 in my 1965 GMC truck. It had the original 306 V6 with a Manual transmission/ 1st is Granny gear. I have the 327 complete all the way to the Bell Housing. The question was asked if the Transmission in the GMC will bolt up to the 327 and is the spline were the same, (1"). My initial answer was YES, but since the question was asked I am having doubts.

I could have sworn that regardless of the engines the GM transmission were all the same during at least that vintage. I remember changing out my 64 Chevy straight 6 to a 283 and everything matched without any problems.

Am I worrying over nothing or could there be the slightest of issues?

Regards,
Mark