Slewfoot 6.0

Ok ive rebuilt my lq4 from the ground up. All still stock except for.the ASA cam, valve springs and high volume oil pump. Im running longtubes on it as well. Its going in my 81 Scottsdale. Im going to run my 4l80 and a 2500 (maybe 3000) stall. Its gonna be carbed with a little spray. Im running 3.42's with a 28 inch tall tire. Does anyone have a similar build. What hp and tq should i see. Also is it possible to get low 20's on hwy. The truck will be mainly street driven, but will also be a weekend warrior. Any advice or info would be appreciated.