LT1 transplant and newb questions
the hardest thing to this swap will be the wiring... you will have to hard wire all the wires going in to the truck for the gauges and AC and all that other dumb tedious stuff..
i can tell you now that this is not going to be an easy project... its going to take time and money of course... but would be worth it in the end... and is not going to have the best gas mileage....
and for as the throttle body... its not going to bennefit a stock motor... you need serious power/ forced induction to help it out... any other questions you can email me at harvickgm@yahoo.com
i will more than likely answer you faster that way..
The two trannies are overwhelmingly the same one is just computer controlled both are OD.
You want the discs swap them to your axle they should both be 8.5" 10 bolts just with different suspension mounts and maybe widths, be aware GM used a drumm proportioning valve on the disc rear cars, that will need modifying if you want properly functioning rear discs since the stock b-body system does not work right.
A 58mmTB would be of no real benifit and would swill no extra fuel.
Not to be an *** but you have a years worth of learning how these systems work before you can dig into them safely and intelligently.
I was young and eager to take on too big a project at one time too, the best thing I can say is STOP and just begin reading all you can for the timebeing.

