The Stovebolt Site Forums The Shop Area The HiPo Shop clifford headers and intake

I came across a used 4 brl intake, with a 2 brl plate. And new long tube headers that were never put on. I am really itching to get this stuff on the 250 but I have some questions.
I am thinking of just adding the headers momentarly and running a true dual 2"exhuast with an x-pipe,not sure on what mufflers yet. but I heard that if you just add headers there is nothing to heat the factory intake and atomize the air to fuel ratio. I've also heard that the colder you can get the air and fuel in the engine the more horsepower you make (hece the cold air intake).
Espically since it is winter do I need to add a heat plate to the factory intake or will it be fine with out anything or shoud i wait intill i have my carburetor and intake set up with a heat plate and do it all at once. My delima is that I don't have a carb yet and don't know which one would be best. and I am really itching to get these headers on and start getting better gas milage and more power.
any imput is appreciated and thanks in advace for any replies.

I would run either the Holly 390 4-barrel, or a Holley 350 2-barrel myself if running a holley. However if I had to buy new, I would look into a throttle body EFI conversion over a carb

Your right, changing the exhaust you loose the carb heat with is helpful in the winter.

I have run vehicles with no carb heat and headers in the winter. I ended up ditching the electric choke for a manual choke to keep it running right in really cold weather.

Those are the two main carbs I'm looking at right now. I'm also considering a 390 quadrajet off an early 4.3 v6. I'm also taking gas milage into consideration when choosing a carb, that points me to the holley 350, and yes I have looked into efi, but $1200 for a kit is to much and I don't have the skills right now to modify a 4.3 system to work but I might in a year or two, who knows. I am changing to a higher thermosat at least for this winter so that should help a little, and by next spring I hope to have an electric fan to hopefully get a few horses. Basicly should I wait intill I have a carb and heat plate for the clifford and do it all at once or can I go ahead with out sacrificing performance and drivability.

I buy my EFI kits used off of Ebay for about $200. I have used 2 so far without a problem on old Jeeps (makes for a better trail vehicle)

>>(hence the cold air intake)<<
You must be thinking CIA. The very first thing everyone puts on their modern cars. Sounds good in the advertisements. Actually they usually do sound good, because you can hear the air intake better. The reality is that most modern Throttle Bodies have hot water(coolant) running thru them so they don't ice up and the ECM can add extra fuel (choke) till the engine warms up.
Leave the thermostat alone, just make sure your choke is working properly so it runs well during warm-up. The only reason to change it would be if it has a 160, because you won't get enough heat for yourself much less the engine. I think a 180 should be used year round.
An electric fan will give you very little if any noticable HP on a street driven 250. Any gain won't be worth the money, when money is an issue.
You have mentioned gas milage several times.
You have not said what the 250 is in.
If you have an old truck with really low gears, that is where improvement will give you the most bang for the buck in terms of milage and driveability.

Unless you take a "whole system" approach to intake, exhaust, and carburetor changes, you're not likely to see much, if any improvement in performance or gas mileage. Try adding one big link to the middle of a chain, and see how much the strength is improved. Running a matched-capacity system, air cleaner to exhaust tips, with a definite goal in mind is the only way to get any significant gain in either power or fuel economy, and getting more power and gas mileage at the same time is a pipe dream. You build for one or the other, and accept whatever the other end of the spectrum provides. I would not consider headers for anything other than a full-competition engine- - - -they're just too much hassle. One possible exception might be cast iron split manifolds, but I would NEVER use a steel-tube header on a street engine. They're too noisy, and I don't like dealing with leaks or changing flange gaskets every few weeks.
Jerry

390 quadrajet
???
What is that?

I agree on the headers - too noisy, only last a few years, clearance problems, not much power increase over split manifolds on a mild engine.

Cold air: most modern cars already have cold air (computer switched exterior vs. pre-heated air controlled by vacuum and throttle position), but the children rip it off and replace it with a piece of PCV and a fake K&N - for $300.

Yes, you should run exhaust heat to the manifold.