Hey, just finished a rebuild on a 4.3L in my dads 1994 GMC Sierra.
Heres some Specs.:
Bored .030" over
Hypereutectic Pistons
Edelbrock Performer intake
Edelbrock Headers
PowerAid TBI spacer
AirAid Cold air Intake
Comp Cam .500" lift, 210 I/215 E duration (@ .050)
Comp Cams roler lifters/pushrods and roller tip rocker arms
1.94/150" Manley Stainless swirl polished valves
New timing chain, balancer, flexplate, motor mounts, alternator,trans mount
Monster Mega 4L60E trans w/ shift kit(capable of 500 hp)
Monster 2300 stall Converter
Summit Aluminum V8 radiator
Twin electric fans
Master Lube oil accumulator
3" single exhuast w/ Magnaflow Hi-flo cat. and Dynomax muffler
Custom burmed PROM chip (180 deg closed loop)
Rebuilt TBI w/ JET adjustable regulator
hers some pics: