Planning to rebuild my 250...

[jim reese]

I need some advise on what parts I might need for my 250 rebuild. I would like to get more out the engine and am aware that the cam, valve assembly, exhaust and carb are all inter-related.

I have the dual outlet header and dual exhaust system already. Given that I would like to use Mike's new head, what cam, valve assembly and two barrel carb I might need.
- Would it be better to go 1.6 lift, roller tip or full roller?
- What diameter valve should I use, as Mike lists two different sizes? Springs?
- What cam would be best to use? I would like a bit better performance, still fairly smooth idle and I need some vacuum as currently I have power brakes and steering.
- I am thinking of using a 2bbl carb, are there reasons to go 4bbl, which 2 bbl would work?

I am sure I have missed a bunch of stuff, any help would be much appreciated.

Jim in MO

 

[rbohm]

- Would it be better to go 1.6 lift, roller tip or full roller?

a 1.6 rocker is they way to go for added lift. full roller is best, but the roller tip works nearly as well for the street.

- What diameter valve should I use, as Mike lists two different sizes? Springs?

for the 250 1.75in/1.50ex are teh valve sizes i recommend.

- What cam would be best to use? I would like a bit better performance, still fairly smooth idle and I need some vacuum as currently I have power brakes and steering.

this is the cam i recommend CSC-264-HDP-10 from classicinlines.com

- I am thinking of using a 2bbl carb, are there reasons to go 4bbl, which 2 bbl would work?

unless you are planning to use the new aluminum head, a 4bbl carb wont fit. if you do use the new head, and want to use a 4bbl carb, i recommend the 390 or 450cfm holley 4bbl carb. these are small enough to maintain airflow velocity, and yet are large enough to feed the 250 with no problem.

I am sure I have missed a bunch of stuff, any help would be much appreciated.

Jim in MO

i recommend that you install a set of 255 ford V8 pistons as they have a proper compression height for the 250 (1.60"). either that or find a set of longer 2.5 hsc connecting rods, and use the stock 200 piston. either way you need to get the piston up in the bore to raise the compression up t where it needs to be, that way you can minimize milling the head.

 

[jim reese]

Thanks for the response. I had the block bored 30 over last time it was done, will the same pistons work.

- Which 2 bbl would you recommend.
- With the valves you recommend, I plan to use Mike's head, what would you recommend for springs, push rods and retainers?
- Timing set? Just go with Mike's?

Thanks again.
Jim

 

[rbohm]

8) if you are going with the new head, then run the 4bbl holley, the 390cfm will do real nice on a street motor. for a 2bbl carb, i have a 2100 autolite on my 66 falcon, but a 2300 holley would also work nice. for springs, retainers, and pushrods get the entire cam kit and the pushrods mike sells. for the timing chain set, may as well stick with what mike sells.