which engine will make 400 hp or more the cheapest. 383 take more machine work. What would it take to make a 350 hit 400 or more cost effectively. I am talking mostly bottom end since I have an rpm intake, but I will need to replace the carb and maybe the heads.What should I bore the 350 out to and what compression should I run.

 

If all you're trying to obtain is 400hp, don't spend the cash on a stroker kit. Bore the 350 .030 over if it needs it, get some aluminum heads that flow well (valves bigger than 1.94/1.50), and flat top pistons with about 10:1 compression will allow you to use pump gas. 041 heads are very good stock heads, but aluminum is lighter and cools better. Plus, you'll spend alot of money making those 302 heads what you need. A cam with somewhere around 230/230 duration @.050 and around .500 lift will make it happen. You'll be in the rpm range where a single plane/dual plane intake is a toss up. Depends on who you talk to. Alot of people will tell you to run a 750cfm carb, I think a tuned 600 will be enough, but it may be easier to just bolt on a 750. Use an electric fuel pump and at least 2.25" dual exhaust, or a large diameter single.

I'm currently working on a similar project, but I'm going to keep the stock pistons, and I'll be using a pair of 415 heads that got bigger valves, p&p, and cc stamped at 51cc. I expect about 375hp max at around 9.9:1 compression. The heads are where the magic happens, so get the best ones you can afford.

 

The Edelbrock RPM combo is good for 420 hp. Thats using their cam, carb, intake, and heads. I believe the RPM cam is a .480 lift. Really not that agressive for the power you get out of it. The RPM carb is a 750. The RPM heads are aluminum with 2.02/1.60 valves. Get a healthy cam, some good flowing heads, a 750 carb, and headers and you'll have your 400+ hp. And at 10:1 compression, you'll be completely streetable on pump gas.

 

Either engine can be built to 400+ hp. and 12 sec quarter mile
performance.
The 350 will need a little more rear gear and a little more stall than an equal 383. The 383 will make more torque than the 350
all else equal.
The power is in the cylinder heads.
The 350cu in motor is much cheaper to build.
You want to build for 10:1 cr for pump gas with cast iron heads.
That would be flat top pistons for a 350 based motor with your 041 (64cc) heads.
your 041 heads are diamonds in the rough.
They will need full porting and 2.02x 1.60 valves and matching valvetrain to your cam choice.
All the cam manufacturers have free email and phone tech advice
to help you get the right cam and kit. give em a call.