I am looking for something like that too, the best I could find so far is from a GM performance parts catalog its a soft touch rev limiter with plug in type modules to limit your rpm.
I have not researched this to see if it requires a computer controled vehicle to run it or if you can just hook it up and use it as is.
Part # is 10039933-RPM Limit Module kit, 5000 series
You can find out at goodwrench.com that is the site listed on the back of the catalog.
I will be running an HEI settup also, so that may be different too