How can I make more HP with my 1973 400 ci engine on a low budget.

Bang-for-the-buck wise the first things I would do are a four barrel carb. in the 600-650 c.f.m. range,a dual exhaust with or without headers, and a small cam upgrade. Don't get carried away with the cam because the low compression ratio won't support too much duration without a big loss in low speed torque.You can also quicken up the distributor advance curve for next to nothing. Look for used parts to save a few bucks where posible,but I wouldn't risk a used cam unless it was from a very well known and trusted source.

Hi,thanks for the information I already did those upgrades minus the cam.I was just wondering if there was anything else besides making a stroker or May be a stroker on a low budget.
Thanks

A 400 is about as low budget to stroke as it gets. A 440 crank can be machined to fit, stock big block rods will work, then aftermarket KB hyper pistons. Will give you a 451. Heck, even if you rebuilt it as a 400, but with higher compression pistons it would make a world of difference.

How creative are you, and what tools do you have at your disposal?


Stock slugs are so far in the hole that a thick head gasket, open heads, and a 440 crank will work.
This is where the 451 originated(so I've been told anyway..)
Problem is, that the ring ridge, will have to be completely removed(and be nice and straight), or else it will go bad in a hurry., and spend some money on machining and balancing. Could still add up.

Another option...
I took a low mile 400, and milled .085" off the block deck. With closed 516's that got me around 10:1 and a little bit of quench.

Scratch hone, and some rings, and It turned out to be a decent little motor that made about 350 hp.

Down side? The intake had to be machined to fit.
Pushrods must be made.

Other than that it was pretty painless, and inexpensive.

Yup, stroke it!