Hey Mike,
There are a number of things you can do to these engines to give them more power. Some of these things pertain more to lower end torque and some do not, but I'll pass on some of what I know.
Aftermarket camshafts can be purchased from a variety of sources, including Iskendarian, and some of the suppliers on
www.p15-d24.com. If you've never looked at that site, you should, as there is a lot of good info to be gained. One of the advertisers there is Edgy Cams and he offers regrinds, and he may be able to grind something specifically for better low-end torque. There are other vendors there who offer cams, too, but I don't think they grind their own, so you may have to buy what they have, if you go with them. Vintage Power Wagons offers a cam and spring kit for about $300, but it is intended to help more with the high-rpm torque, to help the old Power Wagons get going a bit faster down the road.
Edgy Cams also offers a higher compression aluminum head that is supposed to be very nice, but it is also very expensive (I think about $600). You can, of course machine down your stock head to get more compression. I've read that the most you typically want to go for reliability is about 8:1. Years ago, I machined 0.080" off what I believe was a stock head for the 230, and that raised compression from 6.7:1 to 8:1. The engine was bored 0.040" over at the time. I'm currently doing a rebuild of my 230 engine, and my machinist took off a few more thousandths from the head and bored the cylinders to 0.060" over. Now the compression ratio is 8.25:1. Hopefully this is not too much for long head gasket life. I checked the compression by "cc'ing" the head.
Also, you can purchase dual carb intake manifolds for the 230. These manifolds will accommodate two one-barrel carbs. Hot Rod Vintage Parts seems to have the best price for these. Occasionally, you can find headers for these engines, but they are rare. Hot Rod Vintage Parts is supposedly working on some headers for the 230, and they are supposed to ready by this summer. You can even port and polish the intake and exhaust passages. Manifolds, headers, polishing and porting probably get you more power at the top end than at the bottom end.
You can also install electronic ignition, which is supposed to give you a stronger spark for a bit more power. This would probably help at all rpm's. Electronic ignition kits can be adapted to fit the stock distributor. The kits can be bought from Crane Cams and from Pertronix, and maybe others.
A trick I've heard about for improved low-end torque is to advance your cam timing a bit. I'm not sure how this is accomlished, or how much to advance it, but I'm sure some of the other folks on this forum or the suppliers can help you there.
One recommendation I will make: I've been told many times that you should have your engine thoroughly balanced if you ever intend to run at higher rpm's for long periods of time (more than about 2700-2800 rpm), or very high rpm's even for shorter periods (4000 and above).
That's about all I can think of, but then again my knowledge is limited.
Hope this helped.
Matt
