355, AFR 195, xfi 224-230 112, HSR with full bolt ons. Is it worth changing to the Holley 950 ecm or keeping my "730" with an ostrich and tuner pro rt? If I was to change to the Holley what all is needed to make it run with the dash harness and 730 ecm harness?

 

Unless you can get a whole system for $12.00 don't waste you money on a 950. It's tech isn't any better than the stock GM stuff.
If you really want to step up take a look at the new AEM stuff. Wicked fast processor and loads of features.

 

I have a 950 and love it. The harness wasn't that hard to switch out on mine. The engine harness was separate from dash stuff except for a few wires. The 950 is pretty outdated though as far as auto tuning with the newer stuff. I did find a guy that has made an auto tuner for 950 for the fuel map though. It works pretty good. You will lose converter lockup with the 950 but there are other options to control it.