I know this is a recurring subject, but your interest is appreciated...

IPD touts the VX cam as a great way to improve mid-high RPM response in the NA red block engine, with a small loss of low RPM torque, with little to no effect on emissions and fuel consumption.

The VX is popular despite its high (I think excessive) price from IPD, and used VX cams are hard to find (on eBay for example) for less than $100.

A and B cams are easy to find for less than half that price, but they are an older design than the stock M and VX cams. Do they have a similar effect as the VX with respect to torque curve, emissions, and fuel consumption? If so, they would be a much better value for me.

I have a '91 244 (128k miles) which runs perfectly and has the M47 transmission. It has stock engine components and passes smog tests easily. More power would be nice for freeway onramps and staying ahead of tailgating LA drivers. Forget about a really hot camshaft, I need some low end torque for stop and go driving and quiet cruising.