When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Swap meets and wrecking yards are the only suggestions I can offer. FYI- make sure you get one from the '60's. The ones offered on the late '50's model were a smaller carb pattern that todays Holleys.
Hi. I have a 63 F100 (not a unibody) I put a 1957 292 in it from a F700. It came with a 4bbl manifold. There is a web site www.ford-y-block.com that sells them and many other high performance parts for Y-block engines.
You'll need to open the exhaust up if you want to see some benefits from that 4 bbl carb. Valves would be a good start since an engine is, in it's basic form, an air pump.
So, more air intake is only possible if the volume of air comming in can be passed through the engine through the head and exit the exhaust. Although you should see some horspower gain, it wont be near what your expecting.
Good luck swapping everything.