[AC Ventura]

The reason I posted this thread.
I'm based in the UK. I have one of the 480 alloy bodied Mk IVs that Ford and Autokraft built under licence from AC Cars Limited, between '82 and '94. Like most, my car has the 5.0 EFI 302 from the Fox Mustang. The Mk IVs (not Cobra because there was a law suit with Shelby, regarding the name, at the time) were sold as new cars and had to be emission compliant. Obviously the 225 hp EGR, smog etc, ect 302 is quite unfulfilling. In fact potentially embarrassing, is what it is.
So, the default replacement choice is either a 340 hp 302 or a 425 hp331/347 from somebody like Keith Craft. That's the easy option. A simple swap. But I've read that these strokers only get 11-14mpg on a carb.
Therefore I asked the question, what you guys get mpg wise and it seems only 10% worse, which begs the question why not go all out and fit and fit the legendary motor? Well it's not easy in the Mk IV. The chassis, the footwells, the tunnel, everywhere you look there's a problem. Advice from experts here is not encouraging. They all say don't destroy/devalue a valuable car, it will be too hot in the footwells, it will understeer on every bend and will overheat on traffic. Also you'll lose all the boot (trunk) space, cos you'll need a 150 litre fuel tank. But when I hear that I think, no.... the installation that you guys did, overheated and that I'll find a way to do a better job.
It's all made worse by the fact that I've found a good '68 FE 427 that's not been overbored.
One final snag is that we cover 5000 miles in this car all over Europe on competitive rallies and fuel in UK and Europe is $8 a gallon and the std EFI does get 24mpg.
Never the less, I just feel its a 427 body and to hell with what's best. I cant believe I'll regret the big block. Surely it be an event just starting it.
Then somebody says Coyote. That way you'll have 400hp and 20 mpg.................
Anyhow, really agonising here so any advice, do feel free!