Your heads and cam need to be WAY larger. If the compression is there it will make in excess of 625FWHP at about 6800 with a 23* head flowing more than 300CFM and a different intake(NOT LT4 either) Heads should flow 325-335CFM and intake would loose less than 5%(about 15% for stock) A max effort N/A would be in the 700-800+ range with a 15-18* or SB 2.2 head's and custom intake.A mech roller cam in the high 260's or low 270's on a 108+4 for the 18* and depending on the flow of the SB2's for their cam. Some flow in the 360 range some flow in the 450 range.$$$$$$$
If ya want to make HP with that 396 it's gonna cost ya.

 

Yeah, even ported LT1 head castings arn't up to the task of getting enough air into a 383/396.

Then get a cam custom ground for your new heads, something a little bigger than the CC306 should do nicely.

 

a custom cam will make more power than the 306 but i personally know of an MTI 396 stroker with the 306 cam and it put down 433/434. the cam is not the best for that setup but i think he needs to look else where before changing the cam.

 

But, why build a 396 when all it will make is 433? A good 383 will make 450-500RWHP N/A if its right.
The engine ya are refering to probably had more head flow than his.Some porters are doing in excess of 300CFM with stock castings and a LOT of work including welding with 2.0" intake valves.
The CC306 ain't very good for a 355 much less a 396 IMO the cam is very overated.

 

alot bigger than the cc306 its good for mild compression stock cube's but noway for a 396 with 12.1 and up

he is most likely in the same boat is me and needs to keep the heads for another year or two till he can afford them a 396 costs alot and most can only afford ported stockers after the intial stroker motor price mine aint bad 279/230 but will due till i can get the sheet metal intake/heads but for now i am doing a solid roller and this guy needs a large cam also to make any power 380 rwhp is h&c stock s/b terrortory

cam it up and you might hit 450-480 rwhp

 

HAHAHA

 

well i will wait for someone who knows more i talked to ya before and you have a nice car but limited with the mods and always quick to jump on someone like you know everything and been here before

whats 1racerdude think?

 

Sorry, but he can't gain 100rwhp just by changing the cam.

 

i can want to bet? from a cc306 with 13.8:1 compression pushed my dcr up to the point it was like 15.1 compression with my dcr lower it will increase everything and the higher cam will give me about a 100 hp

 

Oh, ok.

 

The LT4 intake want flow as good as a sheet metal intake? Didnt know they make sheet metal intakes for 396's? Loyd Elliott ported Bare Trick Flow castings i sent to him and LT4 intake port matched to them.

 

The LT4 won't cut it on this engine. A 396 is the same as a 350-355-383 LT1 Just more stroke.

 

First, I want to thank everyone for the replies. A lot of good info out there. Anyway, I fully appreciate that a larger head/cam combo would net me larger gains; however, I would like to know if the numbers I ran are low for a CC306 powered 396. Is it possible to put down 400+ in an auto with the 306, or did I make a mistake going with it? Thanks

 

we made a mistake using the cc306 on such a large motor and there are many like us out there that did the same thing

put a 200 shot on it or change the cam

 

I would think that the bare minum you would wanna run on a 396 to make any power would be like a GM 847. And run it with 1.7RRs, with a long duration also since you are on stocks heads still.