Ive got a GMPP 350 HO and im looking to make around 400 NA horsepower with it. What I would like to do is basically leave the bottom end stock, and try swapping heads, intake, carb, and camshaft. I am unsure if the block is roller-cam ready as it sits now, since there is a flat-tappet in there right now. I am using the car basically as a nice summer ride, so I still need some ease in driveability. I have a beefed 700R4 and am in the process of an eaton posi and 3:73 gears in the rear. What do you guys think?

 

I think it sounds good. I don't understand the question but I am all for the build up. 400 hp and 400 ft lbs from a carb combo should not be too rough to achieve. Many options out there. I run fi so I cannot give the best advise about cam and heads combo but others surely will.

 

Im basically just looking for ideas for parts to make it happen. I feel that 400 hp is very do-able, I just need ideas for parts combinations that will work at attain it.

 

Are the heads on the motor the aluminum vette 113 castings or iron?

 

Cast iron vortec heads. The motor is basically stock as it came to me with headers.

 

400 at the crank is doable even with the vortec heads.
keep the lift of the cam under .480 unless you get the guides cut down.if you pull the heads to do that for higher lift,might as well do screw in studs and enlarge the pushrod holes and use guideplates and hardened pushrods.if not,leave them on and think about a duration around 236-242.vortec heads seem to like a split duration cam with about 10*more on the exhaust side.the nitrous specific grinds usually run in that range.the vortec heads seem to reach diminishing returns around .500 anyway,but whatever you do,be sure to check for valve spring coil bind and retainer to guide clearance of at least .060 and better .100!
a lobe center of 106-108 should put you in the ballpark.
performer rpm or offy 360 manifold and a 650 dp or vs and you should be well on your way.
dont forget to match up a nicer quality torque converter!
oh yeah,use the springs the cam company reccomends.
should put you really close!
best of luck,and keep us posted!
Eric