Supersix hop up

[273]

A buddy of mine picked up early 80's 5th Ave with a supersix he's already got a 8.25 with 4.10 in it to swap in we're thinking of 2.5" mandrel bent free flowing exhaust and shift kit and stall speed. It's gonna be a daily driver he wants to keeps the stock intake and exhaust manifold maybe with a little porting.
The main thing is to be able to run on premium gas and be a good daily driver trying to get close too 200hp N/A. So the question is what cam, head mods and compression and how much Nos shot can the stock bottom end with Arp rod bolts handle?

 

[805moparkid]

if he is planning on redoing the whole motor have him do .040 flat tops from summit, then mill the block to get the comp up to 9-9.5:1... no reason to run Plus on a daily...

for the head just gasket match it, same with the intake and exh manifolds...

go stock valves or 1.7/1.44 from ebay... 340 springs will work fine... as for the cam keep it below 230 @ .050 with as much lift as possible...

4.10 might be kinda tall for a daily... a 3.73 or 3.91 might be a little better for hwy/street use...

and ive heard the stock flats will take seasons of a 125 shot...

 

[273]

It's already got 4.10 in it and he rarely go's on the highway.
What kind of power increase would those mods do 175+hp if so with the 125 shot of Nos would be good for the odd street encounter.

 

[RustyRatRod]

Stay away from 9.5 unless he wants to run premium only or have to spike it with race gas. 9.5 with no quench will rattle on super hot in traffic. The number one biggest thing I have read is to be really careful about cam selection.

Overcamming a slant is real easy. Something like [email protected] is probably adequate. Lift as much as you can get because the rockers suck.

About the nitrous.....a good quality cast piston will take a 150 shot all day long IF you don't lean it out lookin for that last little bit....however, you're gonna need richer than what a 2 barrel can provide, I believe.