I think you probably already know more about EEC’s – I for one hadn’t heard of Ford’s EPEC system. Have you tried posting a question on
www.corral.net - Forums. There are some very knowledgeable guys out there and have picked up very useful info as well as some good contacts over time. Another useful contact might be
www.randomtechnology.com who make high flow cats. They’re expensive, but are genuine HIGH FLOW. I bought a couple last year, but have yet to fit them. The intention was to incorporate them in a 2 ½ inch bore system, which I’ve yet to have made. But more important, difficulty with the last emission test has left me nervous about making changes that might worsen the situation. However chatting with one of the technical guys at Random Tech this week he assured me fitting the cats would lower emissions – not raise them – and I could do away with the second pair of cat currently fitted.
Regarding the choice of heads I would suggest AFR’s. They, and Trickflow Twisted Wedge, are currently considered the best flowing heads by our American cousins. And from all the flow charts I’ve unearthed AFR’s flow pretty much the best – both inlet and exhaust. Personally, I went for 165’s. 185 heads, as I recall, bias power towards the top end to the detriment of mid range - OK for racing, but not so good for practical road use. Also the 5.0L is not, in my opinion, a sweet revving engine. Take a look at the valve gear - its HEAVY compared to European engineering - and above 5,000 rpm it becomes audible making the engine sound harsh. (Contentious stuff I know!) Useful power gains are to had ensuring the upper and lower manifold align, same with the lower manifold to head ports. The lower manifold in particular was a poor fit and I spent a lot of time “porting” them, and even went to the extent of making thinner manifold gaskets so the ports still aligned correctly with the manifold fully tightened
None of the above helps particularly with your original question, but may be some interest. The answer is probably a twEEcer coupled with someone brilliant on computers who can advise how to set it up, interpret the jargon and datalog results.
Cheers
Max
PS Which Edelbrock timing gears did you go for – the silent or noisy?