2.6L sigma or sigma gsr question...

hey!

I have a 76 galant, nice n green n all! It's all standard from waaaay back then! I've managed to get my hands on a big rx turbs for a really good price. I originally wanted to get mani's made up to fit my current 1600cc engine but it needs a rebuild before i should consider that, and all the costs added up I might as well buy a new engine ( i probably woulda blown it up with the turbs anyway! )... I wanna stay in the 4 cyls... I'm told that the sigma engines should bolt straight in with no big problems but my mate wasn't 100% sure. I'm just wondering if anyone else knows anything about this!

I currently have my eyes on the 2.6L sigma engine or the sigma gsr..... :?