352 For The Highway

[chris401]

Good evening. Drifter from fordfe here with an intake question for my 65 F250 4spd, 4.10s. Future build: stock C0AE flat tops, C7AE-A heads (rebuilt), 252H and C2 Shortys. Looking at Jays test data it looks like the Edelbrock SP2P would be a better choice over the Offy Dual Port due to port hieght for secondaries . Any sugestions this side of a 300 six?
Thanks, Chris

[jayb]

Can you give more details about what you are trying to accomplish?  Are you looking at those two intakes because mileage is your chief interest?  If so, I'd go with the SP2P.  But if you are concerned about maximizing low end torque, I think I'd be looking at an Edelbrock Performer (not a Performer RPM).

[chris401]

I'm looking for mileage. 3,000 rpms @ 70 mph. I may be driving annual mileage from 11 to 33k. Its suited up for most trailers now but towing isn't my concern at this time. I also have a 390 Holley. Would this be a good complement to the SP2P?
Thanks,
Chris

[jayb]

The SP2P is your best bet if mileage is the major concern, and I think the 390 Holley would work fine with it.

[chris401]

Appreciate the info. All I'm missing is the cam and intake. I have a couple of factory cams that will hopefully grind to the 252h cam specks.
Thanks again

[drdano]

I'll get flack for even suggesting this, but I'd be looking at using a 750 quadrajet on such a build.  Tiny primaries and adjustable APT setting would make it a super gas sipper on the highway and have some roar with the bigger secondaries.  Food for thought, just dont throw the food at me.   

[machoneman]

What? A Quadrajunk! Heresy, I say! Draw and quarter him! 

Actually, that is great advice and a well set up Q-Jet would be the best ticket for mileage. The only issue is few these days know how to set the jetting and other parameters unique to this style of carb (at least compared to a wider knowledge base among Holley fans).  If you have access to a Q-Jet guru or a known supplier of well rebuilt units I'd go for it. 

[chris401]

Good suggestion. The Rodchester design has crossed my mind.

[BruceS]

Chris,
If towing is not a big concern and you're looking for mileage how bout a taller gear?  If you're running 4.10s you've got an opportunity there, say even going down to 3.50 or 3.25. My Galaxie came stock with a 3.00, and the Fairlane with a 2.70!

Bruce

[lovehamr]

An over drive trans would be high on my list as well.

[drdano]

What? A Quadrajunk! Heresy, I say! Draw and quarter him! 

Actually, that is great advice and a well set up Q-Jet would be the best ticket for mileage. The only issue is few these days know how to set the jetting and other parameters unique to this style of carb (at least compared to a wider knowledge base among Holley fans).  If you have access to a Q-Jet guru or a known supplier of well rebuilt units I'd go for it.

Pitchforks, Aye!  Get the torches!   

For such a mild engine as this 352 is looking to be given the specs above, I'd say an OEM 750 (smaller of the two q-jets) rebuild from a good core would be my route.  Jetting changes are pretty simple once you've done them a few times.  If he's not comfortable with doing the rebuild, I'd highly suggest some of the performance carb guys out there like Dean Oliver or Sean Murphy.  Sean did my original 750 on my stock-ish 390 and it ran perfect and I saw 20mpg on the highway with 3.00 gears.  Dean built the 800 I'm running on my new 428 that is pretty warmed over and makes lame vacuum at idle with the big roller cam.  It runs perfect and I've seen very good mileage with it as well.  Regardless, the small primary bores, particularly on the 750cfm carbs make them very attractive for something mileage oriented.  The APT setting also makes the primary rod depth infinitely adjustable when you're humming down the highway, so you can get every last mpg possible very easily provided the secondaries are shut at highway speed.

[chris401]

The axel is a Dana 60. 3.73 and a GV may be in the future.
Thanks

[chris401]

Parts I'm coming across have dictated my direction. For now the short stroke will be in place and the original 352 be set aside for future build. I have located a Doug-Nash under drive box which will complement a NV4500 with 3.54 in the rear. Employing the under drive gives me a 4.24:1 axel ratio for towing. 3.54 OD will put me about 1890 rpm @ 70mph. But for now the 4 speed, 4.10's, short stroke and SP2P will be the motivation.

The axel is a Dana 60. 3.73 and a GV may be in the future.
Thanks

[chris401]

I also picked up a reman Q-Jet from a 350

I'll get flack for even suggesting this, but I'd be looking at using a 750 quadrajet on such a build.  Tiny primaries and adjustable APT setting would make it a super gas sipper on the highway and have some roar with the bigger secondaries.  Food for thought, just dont throw the food at me.   

[cammerfe]

They're long out of print but you might try to find a Holley 6708. It's a special-purpose 650 DP that has big-'n'-little butterflies. I used one on a tinkered-with 302 in a '72 E-150 and it did excellently on the h'-way. You can modulate with your foot and stay out of the secondaries, but have a little extra when you need it. And I agree with Jay regarding the regular instead of RPM manifold. And there's too much of the band-aid to the odd-ball designs.

KS