Hi kewolfe,

Thanks for your reply. It sounds like 2" pipes and quality tri y's would be fine for my application.

The piston height was identical to the original pistons, altough we lost a bit of compression because the much larger valve reliefs.

The cam is from Clevite, but it is the same as the Edelbrock Performer cam and the Summit SUM-3600 cam for instance. It has .448/.472 valve lift, and a 112 degree lobe seperation.
It's a very mild cam, so I wasn't expecting miracles, but the car is performing noticably worse then the propane run c-code 289 in my '66 hardtop which is completely stock except for a pair of cheap tri-y's and 2" dual exhausts.
The car will be used for cruising 90% of the time, so it will spend most of it's life between 1500-3000rpm. I don't plan on running the engine beyond 5500rpm at all, so the cam seemed like a good choice, just like dual exhausts and a pair of tri-y's.

I just got Bob Mannels book 'Mustang & Ford Small
Block V8'in the mail today. He lists 4 Ford technical service bulletins on the 4300 carb, all about reducing bogging, stalling and hesitation on acceleration. I'll take a look next week to see if any of these adjustments were made to my carb.