I'm just about done with this phase on my car. Still waiting on my replated booster to come back from Steve at Brakebooster.com. Anyway this is what I have now in my car.
Original block 396 + .030
stock domed pistons 10:25 CR
stock heads with 3 angle valve job
Speed-Pro heavy duty double roller timing chain and sprockets
Speed-Pro Pro 5000 series hyd camshaft with new lifters and springs
Specs on cam are:
intake lift .579 exhaust lift 553
duration @ .050 intake .234 exhaust .244
advertised duration intake 312 exhaust 322
lobe centers are intake 107 exhaust 117
Pertronix Ignitor II in my stock distibutor with Ignitor II coil
Original TH-400 with 2800 stall converter
Original 12 bolt with 3:31 Eaton posi
Stock cast iron intake
Stage II SMI Rochester with mods for my camshaft
stock exhaust manifolds
2.5" dual exhaust with Series 40 Flowmasters (soon to be changed) because of interior noise
I haven't got to test drive yet (no brakes) but the engine seems to rev ALOT quicker than before. The idle is pretty nasty but not to bad. Has a stong deep choppy sound that I like.
What kind of horsepower gains can I expect over my stock 325 horse motor with no more than I've done so far?
Jody

425 HP/450 ft lb torque

I don't think your combo will see much over 370 HP due to 2 main weaknesses:

1. stock cast iron intake ( need an Edelbrock dual-plane RPM intake)
2. stock exhaust manifolds (need small tube headers)

These items will basically suffocate the engine and not allow it to breath under hard acceleration. It may also be a "dog" down low with that high cam duration combined with the tall 3:31 gear.

Charles

I ran 331's iwith just as much cam in the past in my 396 with all the same stock intake/q-jet,stock ex manifolds and it was fine,dont worry.

But make sure your running enough intial advance like 16-18 deg btdc with that cam in your 396.

Whats heads are you running,063's,290's lgr oval port with 100 cc chambers?

I would est with that motor on a dyno with the stock ex manifolds on it real roughly 370-390hp/425-440 ft lbs trq.

Remember all is bone stock in your motor accept for running a lot more cam than the 325hp had along with running a specially prepaired Sean Muroy q-jet and thats it.

Now if you did some pocket porting on the heads,installed undercut raceflow valves for better flow,had your stock cast ex manifolds & intake extrude honed for better flow or ran headers & perf q-jet rpm intake you would be looking at more like 385-425hp/430-450 ft lbs trq.

But even at my lower 370-390hp/425-440 lbs trq est for your motor it will feel a lot stronger than the 325hp setup did which i can tell you from experience.

You are running a fair amount more cam than me right now but with basically the same motor setup (& 3:31's) inc both of us running Sean murphy ind q-jets specifically set up for our motors/cams my 396/325 now runs a lot stronger than it used to.

My cam is a comp cams hyd flat tappet 222/226 deg dur @.05,.525/.525 lift,112 L/S angle and it gets out of its own way real nicely now. You have more cam than i do but i did have mild pocket porting done,used undercut valves for better flow,and had my stock ex manifolds extrude honed for better flow so you have more cam but i have a little better breathing capabilites on both ends in & out which will have evened us out some on the perf end.

So with all that said i think you will be happy with the perf gain you will see whencompaired to the old 325hp perf lvl.

Again,dont forget to make sure your running enough initial advance with that cam like 16-18 deg btd with the motor at low idle & vac adv unhooked & plugged while setting the intial timing and then dont forget to hook the vac adv back up when done.

After you set the timing could you take a vacuum reading at idle to let me know what it is with that cam,id appreaciate it?

Let us know how the new motor feels with that fairly hot cam & Sean Murphy specially prepaired q-jet,i think you will be pleasantly surprised.

Scott

One question: Are you using the stock single snorkel air cleaner? If so, that will strangle the engine at upper rpm. That little opening can't flow enough air to feed your engine's increased demand (couldn't even flow enough for a STOCK 325 hp). You can cut or drill holes in the bottom of the air cleaner housing, outside the filter element, to increase air flow while being out of sight and still original appearing. The reason for the snorkel air cleaner on 325 hp engines was for noise control. I'm guessing you don't mind a little carb sound at this point.

Von,good point ,thats why i run the 396/375hp open element ait cleaner with a K&N filter on my motor and i store the stock 325hp air cleaner in a box for safe keeping.

Scott

Von, the car has the open air cleaner which was on the car when I got it. Like I said, still can't drive the car but I've noticed it's throttle reponse is so much quicker than before. Kinda reminds me of a two stroke the way it gets rpm so fast. Might be a different story when I drive it. It runs so much better now I can't help but think it'll be a big improvement. I know with a good intake and some headers it would make more power but I really like the stock look.
BTW Scott timing is set to 18 initial and idles with 12-13 vacuum. Thanks for the input and advice.
I was hoping for a little over 400 horses.
Jody

Jody, Sounds like a good combo. I'd put a 350 hp decal on the air cleaner, since that's what it looks closest to. The stock 325 hp cam was very docile. Meant for quiet, smooth operation in the big cars. It's specs were like a stock 307/327/350.

Hey, Jody. How 'bout getting some chassis dyno numbers on your car after you get everything running and post them. We'd sure like to know how much power this street combo produces with everything you listed (specifically with the stock intake and exhaust manifolds).

I still respectfully submit that you are well under your 400HP mark 'cause that motor will be restricted and not breathe well above 5000 rpms. I also have a 396 and received experienced advice from many people about restrictive components when building a fresh BBC, so I built mine to breathe and I'm glad I did!

Charles