Slick 60's

Which intake is preferred the Clifford or the Offenhauser for the 240/300 engines? What size 4bl carb should I use with either of the intakes (no upgrades done to motor) and who makes quality headers for the 240/300? Will a late model exhaust manifold work with the Clifford/Offenhauser? Thanks for your time and thoughts.

I am in the process of putting on a Clifford intake and I am using later model split exhaust manifolds. I have a no mod motor and have been advised to stay with a 500 cfm or less carb.
As for which intake is preferred I do not know. But the only issue I have had with the Clifford and the exhaust I am using is I had to clearance under one intake runner to have room for a washer to fit. Other than that all bolts right up. I will complete mine once I finish making exhaust connections, even though it sounds pretty tough with open exhaust.
The same man I bought the intake from in Ohio does have a set of headers for 50 bucks I just could not afford them with the shipping at this time.

I am in the process of going with the Clifford setup for my 240cid. Intake, headers, Holley 390cfm. Holley part number is 0-8007 (http://www.holley.com/0-8007.asp). Will upgrade to a 300cid when the someday-money-fairy shows up. Clifford offers ceramic coated headers (extra charge) which I'm hoping will help with heat transfer and scavenging out of the classically restricted head on the 240/300.

Had extensive talks with Larry at Clifford re: carb setups and offerings (holley / weber / demon / etc). Decided to go with the Holley and here is the setup info:

240 cu. in. 8.5 POWER VALVE .031 (tube type) discharge nozzle .048 main jets

300 cu. in.  8.5 power valve .035 (tube type) discharge nozzle .052 main jets.

May not be perfect, but a great place to start the tuning.

Thanks for the input guys, I appreciate it! I am moving to San Antonio in August and I would love to meet up with you and check out the truck! I have a 66 F250 4x4, but it will not be there until October or so. Thanks again.

The offy will perform/flow better at the top end. I do notice that mine like to be above 2500.

there is a web site called ford six I think,and some of them use chevy 250/292 six rocker arms and balls because they have aa 1.76 rocker arm ratio and are good for 0.030 or 0.040 extra lift and a couple of deg.duration and its cheap!I think it only works on pre fuel inj.cyl heads.I forget the particulars but they have a lot of good info on 6 bangers even 223's and 262's just google ford six,you should find it pretty easy.
Dave

fordsix.com

Lots of good info over there. I don't go over there much any more now that mine is built.