I made a 347 from a 289 last year, i put in an Eagle kit with the 5,4 rods 4334 crank and forged SRP pistons. with 351 w heads with big stainless valves, some porting, a set of tri y hedders, a mallory unilite distributor, Edelbrock single plain intake and an Edelbrock 650 carb with manual choke.
This works fine, sofar i have had about 1000 miles of pure pleasurecruising in the car, 1966 Galaxie 2 dr. HT, and there have been no problems.
The kit was easy to install, The guys at Eagle was very nice and when i snapped a pistonring, they told me "no problem we will ship a couple of rings pronto" so as you can tell i am very pleased with Eagle, the product and the service.
So as soon as i find a 1964-1968 mustang convertibleproject, i´ll build another strokerengine, this time a 427 BOSS setup on a 351w block..