what can i expect from a new 63mm bored throttle body and 4 hole injectors?

About a $300 or better lighter wallet.

Seriously, contact www.strokedjeep.com for the throttle body and "programbo" here on CF for the injectors.

Not much unless your old injectors are clogged. You will have slightly better response and the tb might whistle sometimes. I don't keep track of mpgs. No regrets here. Throw on a hot air or cowl intake while you're at it.

www.strokedjeep.com sells bored throttle bodies minus the whistle.

The Renix and early HO injectors only had one spray port in the nozzle, and were prone to leaking fuel externally through a seam. Some engine fires resulted from that.

An injector doesn't have to be "clogged" to minimize it's performance. A poor spray pattern, reduced flow etc can cause performance reductions and idle quality issues.