Trans (&engine) install ?'s (anyone near Sacramento willing to come by & help?)

Not sure what you read about truck transmissions needing trimmed but you don't want to cut those off. Their there for mounting it to a work station. That output yoke in your link is for the large 7290 U-joint. Nearly all A-body's used the small 7260 U-joints but since I have no idea what driveshaft you actually have I can't say if that's the right yoke or not, other than 30 spines is correct. You need to measure the I.D. of the u-joint yoke on the driveshaft to verify what you need. If the I.D. measures 2-1/8" it's the small 7260 u-joint. If it measures 2-5/8" it's the larger 7290 u-joint. Here's a link to the small u-joint yoke in case you need it. I also attached a picture showing what I'm talking about measuring..

http://www.summitracing.com/parts/ied-sy-727-7260

Next question is what engine are you running and what torque converter are you using? If your using the stock torque converter that came with that transmission it'll only work on a 360 LA engine, unless it's been modified. 360 engines were externally balanced by welding a piece of steel onto the torque converter. If that's what you have and you try to use it with any other engine it will be out of balance and vibrate like crazy eventually destroying the engine and possibly the trans.

Not sure on the differences between the super comps and the standard Hooker competition headers but I had the standard comps on my car until recently and when I put it together I used the mini starter. It was hard enough to get in and out. Hate to think how hard a stock starter would be to get in there. Mine didn't require the indexable starter. Once in it cleared things fine.