Building my 74 duster

Hey guys I am putting together a 360 engine for my duster, it recently had a slant 6 inside. So I also got a 727 trans to go with It. I tried getting a 8 3/4 rear end, but here in Los Angeles CA it's almost impossible to find that. So I just had the 8 1/4 built. I put a auburn posi, with 373 gears and Dutchman axles.

The transmission 727 , I had it built up with a stage 2 street strip b&m shift kit.

And the 360 I got edelbrock rpm performer heads, with a super victor jr intake, a 800 thunder series carb,

And internally I got KB pistons with a ISKY racing cam

The car was just dropped off to the shop this Monday, they will possibly start working on it next week, my question to you guys is, do you guys think this was a good set up ? Im not to technical and familiar with ratios and dyno sheets, so I just want to get feedback on my engine I rebuilt ? Is there any thing you guys would sudgest I do ? My only concern is not getting the results I expected, when the ship built my motor it would be expected to push about 425 horses, Id be happy at least to push 400 horses. What do y'all think?

Also I'm not sure with what exhaust to go with.... I'm getting hooker headers, and as far as the exhaust my 2 options Im thinking about is either SLP, or borla exhaust... What do you guys sudgest ?