hey fellow ford enthusiasts. im new to this website, but i have a account at another site. this sight looks to provide better info on the older fords. i have a 1977 250 highboy im working on. i recenlty took the engine back out. itwas just rebuilt by the previous owner. the specs are, 1971 block .30over. 400, mild cam, port and poilshed heads, edelbrock performer, 750cfm edelbrock carb. my objective is to increase overall performace. my thoughts are new distibutor,wires and carb. my problems is what size carb to go with. some guys say a 750 is to big. i know there is a 650 eldelbrock or a 670 and 700 holley out there. i think the 700 is a double pumper and not sure how well that would work. what about the secondaries. is it better to go with vacumn or mechanical. ive read some other post on here about the debate on a high volumn oil oil pumps, and the deeper milodon oil pans, and even an oil cooler. a lot of you say its not really worth it? what other enhancets can i do to make it run better?
The thing I've done to my 79 with a 400M that really helped is an HEI distributer. I'd think 0.30 over would be fine, with a mild cam, something with a nice lobe to it. I'm running an alluminum intake manifold, and Edlebrock 650, 4bbl with mechanical secondaries. Headers, 3" exhaust, then 5" stacks. Abit extreme in the cab though.
I don't think a carb alone is gonna be the magical fix. 750 is a tad too big, IMO. That said, a "straight-up" timing set is a good start, along with the cam choice of being a Comp DEH 255. You say mild cam, but do you know what it is? compression ratio? pistons? etc... With more specifics, the gurus on this forum can dial that baby in to a tee. Which in turn will give you a better answer for carb choice. And welcome to FTE!!!
ive read the other post on the debate on the high volume oil pumps. i really dont know if it would be worth it or not? what do you guys think of the 650 edelbrock thunder series avs? another thing is i have to get this motor passed emmisions once cause i got collector plates? i know right now there is no emmisons controls left? what to do. retard timing, run lean, and a little race gas?
hi jmm, paul here. i have no intent to discourage you, honestly i am behind 100% any one who has the gumption and the will to make these motors romp. i still say the confusion over the h-v pumps is related STRICTLY to STOCK pan APPS. h_vs ARE GOOD IF you can keep them fed IT, is THE stock PAN with that go fast pump where WE get in trouble. I honestly believe my mouth. those big time pumps run short on available oil quick with stock pans. then you areate and goodbye babbits, even for an instant.with air, you lose your boundary layer and its all over, particulary under load. i am bullheaded on this point but so help me i believe it just my thoughts bro just mine and mine alone. ah-v with a deep sump ie more volumne OVER top of your pickup will or should prevent areation and/ or starvation, i reamind you, your root clearences are ALWAYS a determing factor in proper oil control.bottom line we pull for YOU and good luck ALWAYS its a tough world with uncle sam lookin over your shoulder. as always, paul & nickk MD,l
I love my Holley 650 Double Pumper. Worked wonders on my engine. (400, .060 over, .484/.510 cam, 7.9-8.0:1 CR)
Good luck with emissions, i know in my state the vehicle has to pass the visual inspection before ever being hooked up to the sniffer. If all the OEM smog junk isn't on there, it fails the test right then and there, regardless of actual pollutant levels.