I6 carb and tranny questions for a Newbie...

[flawedchemical]

I just picked up an old 70 F-100 from the original owner with 75k miles and a super straight body. It's a straight side custom, red with a white top and a 240 I-6 and auto tranny...I think it's a C4 from what I can tell...that's one of my questions. My other question is about the carb...It's shot...should I get another stocker or the holley I see hanging around or any other option you guys know about?

Thanks,
Jeff

[fordman]

heres the trans pan guide. the carb deal is up to you. http://www.fordification.com/tech/image ... nsID07.gif

[flawedchemical]

I found the pan guide and tranny ID page but it's kinda gunky and hard to tell...I don't think it's a cruise o matic or a c3 by the pics and the center section is not cast iron from what I can tell...my magnet was kinda weak haha

[Dragon]

Hard to beat an Offy Dual port manifold and 4V over the stock 1V and the mileage will stay the same and the power will go way up.

http://www.summitracing.com/parts/OFY-6019DP/
http://www.summitracing.com/parts/HLY-0-8007/

I stuck the same manifold on my Dad's 69 F100 and we dropped over 3 seconds in the quarter and gained 17 mph the truck climbed a mountain pass with 1200 lbs of hay and almost 2000 pounds of horses and trailer in 3rd that with 400 pounds less and the 1V climbed the same pass in 2nd gear. At the time I was a young buck and we stuck a 780 holley on the truck and it was way too much but it got us to the speed shop to get the 600 Holley that we ended up using. Now days the engine calculations show us that the right size carb for a 240 is 236 cfm but the manifold require a 4 barrel to work properly and the smallest 4 barrel is the 390. The fact that the 600 had vacuum secondaries allowed it to work well and not bog. The 390 will work even better.

[flawedchemical]

That looks awesome but I'm kinda on a budget right now and something stockish would be better right now...but that manifold is awesome and definitely in the future

[Dragon]

Well a stock carb and believe me the original carb has worn throttle shafts and won't rebuild any better than it is because of the vacuum leaks.

http://www.summitracing.com/search/make ... Rank%7cAsc

This is the best deal and will work great. Holley can really rebuild carbs and they do it right. Autozone, Oreilly's and napaonine who is even more.

https://napaonline.com/Search/Results.a ... tk=Keyword

[fordman]

just look at the shape of the trans pan to heck what the case is made out of. that just means it might be a mx or an fmx if its the same shape pan.

[flawedchemical]

That carb looks good...it's probably what I'll get and looks like I'm gonna have to get dirty and clean that tranny to get a good look at that pan

[fordboy69]

If your original carb is in decent shape you could just go and get a rebuild kit for around $20-$30 bucks, and clean out the carb and rebuild it. The 1v and 2v Motocraft carbs are really easy to rebuild. Just a suggestion.

[flawedchemical]

I already rebuilt it but the throttle shaft is leaking and also from somewhere else still...and the accelerator pump doesn't work properly...Ithink it's time for a new one.

[Dragon]

If your original carb is in decent shape you could just go and get a rebuild kit for around $20-$30 bucks, and clean out the carb and rebuild it. The 1v and 2v Motocraft carbs are really easy to rebuild. Just a suggestion.

Any carb over 90,000 miles or 20 years is guaranteed to not be user rebuildable as the throttle shafts are wore out and will have vacuum leaks you won't be able to fix because of that.

[killakobra]

yea.... those one barrels are a pain and more expencive than a 4v. about 2 weeks away from upgrading.

[Dragon]

As a sideline to my racing and Big Block race motor shop I took on rebuilding and speciality tweaking of Holleys. Well about 1984 I started seeing all these mid and late sixties carbs that people could not rebuild and after a couple of weeks of being baffled I finally really tested one on the flow bench rather than rebuild and tweak. What a joke some throttle shafts were leaking so much air that the engine test required the idle needles to be backed out at least 3/4 of their tapered needle's length to overcome throttle shaft leakage. At that time throttle plates were available but so expensive that a new carb was only 50% more then the repair with a new throttle plate

The real hassle was some shafts don't leak at an idle as much as at a higher opening. If the carbs were regularly driven at say 50 mph for most of 15 years then the wear was at that point and when the throttle was closed or opened farther the wear spots fell on normally shaped areas and dropped the leak way down throwing off calibration.

[flawedchemical]

That's good to know now...I'm torn between getting a rebuilt 1 barrel or an offy manifold with the 390 holley???

[DuckRyder]

You might try the classifieds over at fordsix.com, it is possible you could pick up at least the manifold used... I personally would probably go for a new or Holley reman carb for it, but the manifolds shouldn't go bad...