Originally Posted by flipklos

In my mind using what I know a 100hp gain out of the 300 is very attainable.
So it was a 130 horse engine now its a 230 horse.

A 300 hp 300 is attainable. Though it would be cost prohibitive. A simple 4bbl, headers or EFI pipes, and a 260 cam should put you up to a clean usuable 180 hp with about 300ftlbs on tap. Porting and polishing and dumping a hotter ignition would give you another30-60hp and proboly about an addition 20-50ftlbs. So a realisticly predictiable power for a build like hgb4x4 is in the 200-240hp with a torque in the 290-340 range.

Lumpier cams, compression increases, big valves and rocker arms could realisticly give it 300 hp and close to 400ftlbs. Add some boot at a reasonable level and one could push both numbers up by 50 I would think.

One problom is where is the powerband sitting. If your powerband is starting to sit over 3000rpm you have just ruined the driveability of the engine. Why do you think that the 460 had better power than the 351W? It only rated about 40hp more than the windsor. The thing was the windsor produced its power at a higher rpm than the 460 making it perform less admraibly. (I like the windsor.)

Other than using the oversized exhausts all you guys have logical numbers if they are used in their propper contexts.
I am not a guy that rods the gills out of their vehicle. A true 20-30 horse gain with a 5% increase in economy is much better than a 100 horse gain with no change in economy.
I am still battling away on my 2bbl intake that I am making. It is going to mount a 265cfm holley 2bbl and use EFI manifolds. Expected performance gain with the comp 252 cam I got.......15-40 horses. But I expect my milage to improve slightly over the YFA and get rid of teh terrible lean stumble that the YFA gives me during the cold months that plauge ND.