Yes this tranmission has the typical Chevy/GM bolt pattern. It bolts right up to the old heavy duty cast iron GM truck bellhousing, even though the bellhousing from the factory was aluminum.
I have a 3.73 geared rear end and I notice little difference with the 3.09 first gear of the New Process vs. the 2.85 first of the old 3 speed. My engine is larger than I had with the old trans and the cam is stronger so it may be that I can just rev out first gear further with the engine mods.
I almost was tricked into a Granny 4 speed at a salvage yard in Alabama a couple of years ago when I was looking for one of these. Fortunately Tony P had already posted a picture of his at the Stovebolt website so I knew what to look for. I also knew that none of the New Process tranmissions had a top-loaded shifter. The New process will also have a 10 bolt side cover. Most salvage yard guys probably don't even know these tranmissions ever existed so you can't count on them to know what to look for. If you're fortunate you'll be able to snag one of these for an 4 cyl S-10 T5 price.
-magic mike-