521 heavy tow build

I'm putting together a 521 for my 93 f350 as a backup for hauling my 41 foot top deck 3 car trailer. Trucks going to have a zf and 3.73 gears...  Going to use throttle body fuel injection. Have a stroker kit with kb402 pistons. Trying to decide which heads to use... I have 3 sets to choose from.. I have a set of procomps that are pocket ported with good Ferrera 2.19 1.71 valves. A set of large valve d3's with the exhaust ports cleaned up and a stock set of f3.... Also have 2 voodoo cams 701 and 702. For intakes I have a performer, an air gap, and a weiand stealth non cj. Truck will be pulling 16-18k. Combined weight will be 22-24k. Trying to decide which heads, intake, and cam to use. Engine will spend the minority of time under 3500 rpm. Would like to use no higher than 89 octane. Trying to keep the compression down so pistons will be .010-.020 below deck.... Any suggestions would be appreciated... Shooting for 600+ ft lbs

What kinda weight and frontal area you talking?

16-18k trailer weight... Frontal area will only be occasionally when I have a car up on the deck that's over the gooseneck. The 2 on the bottom of the trailer are low partially below the truck cab

I’d be looking at less aggressive cams with wide lob centers, something custom.

Keep the compression around 8.5:1

I’d also do a light port and match on the D3 and use very high quality exhaust valves. With the heat I’d be afraid of the procomp dropping seats and they don’t flow any better than factory iron.

Edelbrock performer or a stock iron intake

SS banks or some similar high quality headers

I'm going to be right around 9:1 with the pistons I have.. both cams are on a 112 LSA should I shoot for 114?.... I do have the comp speed density cam that's smaller on a 114

Bosskk1786 wrote:I'm going to be right around 9:1 with the pistons I have.. both cams are on a 112 LSA should I shoot for 114?.... I do have the comp speed density cam that's smaller on a 114

You need to watch the dynamic compression, the 89 and loading are going on go be tough on the engine

600 foot/lbs and 89 octane I would go with the 702 out of the three. 4.10 gears would be nice also.

The 702 was the one I was leaning towards cause of the extra cubes... I can just keep my 4.10's. was thinking with the added power I would turn 1900 at 60-65 instead of 21-2200

You can run your dynamic compression on here.

http://www.wallaceracing.com/dynamic-cr.php

Run your cam spec's on this one at .050" duration to calculate if you don't have them.

https://www.summitracing.com/newsandevents/calcsandtools/summit-cam-timing-calculator

The lowest was the 702 when I ran them.

Run all three cams though the Summit calculator first.

I assumed this was the Comp Cam you might of had?

https://www.compcams.com/xtreme-energy-computer-controlled-hydraulic-flat-cam-for-ford-429-460.html

The events in the link don't jive with the Summit calculator and come out at 36 degree's close.

Double check it though.

You dont want to lug a gas engine with the loading you looking at .

Ok I'll keep the 4.10's.... yes the comp cam is another one I have. I'll run the #'s through for dynamic compression calculator I have the cam cards..... I'll run the Edelbrock performer intake with an open spacer...

If you go by the Comp Cam Card and the intake valve closing event is 58 like in the Summit link you will get around 7.59/1 Dynamic Compression. I was always leary over some of their numbers. The Lunati's where coming in around 8.4 and 8.5 using the Summit calculator. It would be interesting to see the actual cam card numbers between the 3 cams on the intake closing events, if you get time to share them.

PS: I ran the Advance at 4 degree's, in the Summit Cam Calculator, as all three cams Intake center line were 4 degree's advanced from the Lobe Seperation Angle. IE 108 for the Lunati's and 110 for the Comp Cam.

Ok... I'll try to figure out how take a picture of them and post them up

Using any other heads on that truck other than F.I. heads becomes an issue with almost every other part you will want to use.
Been there ... done that; not preferable.

I would use your F3 heads with some S.I. larger 2.11" intake valves installed with stock size exhaust valves ... pocket port both sides.
Part throttle TORQUE & mileage is what you need not Wide Open Throttle Horsepower.

Port your STOCK F.I. intake, (especially the injector bungs  and lower runners) and install 1/2" welsh plugs with Locktite where the injectors use to be.

Fabricate your own or buy a "Price Motorsport", (or other brand carb adapter available), for that manifold to be able to install your TBI easily. (I used a "Sniper" TBI).

The camshaft is important NOT to be too big: TOWING torque is where it has to be with some passing ability.
Your 10340701 will work well.

Keep your actual compression ratio around 9.2/1 or less.

I have the price motorsports adapter for the bigger throttle blades and headers for the f3 heads....... I've seen some impressive #'s posted with the f3 on strokers.. if I zero deck the block compression will be 9.4 ish with a 95 cc chamber

Bosskk1786 wrote:I have the price motorsports adapter for the bigger throttle blades and headers for the f3 heads....... I've seen some impressive #'s posted with the f3 on strokers.. if I zero deck the block compression will be 9.4 ish with a 95 cc chamber

The "93 customers F-250, 4-door truck, 521" engine I built like this had a 41' Haulmark "gooseneck" trailer but, I don't know the actual weights of that package.

That 701 cam, (109 was where in went-in "dot to dot"), was the right size for his 3.89/1 Gears on the highway for mileage; 4,10" would definitely pull harder but, mileage would certainly suffer running it higher.

I later changed it from a CompCams 270H, which was just "to big" below 2,400 RPM with the Hooker Headers.

I have another new set of those F.I head, 6842HKR full length Super Competition Hooker Heades; 1 7/8" x 30" ... 3" collector.

Thanks Randy that's the kind of info I was looking for... I have hooker headers for the fuelie heads.. I could probably use my stamped steel rockers also, correct?

Bosskk1786 wrote:Thanks Randy that's the kind of info I was looking for... I have hooker headers for the fuelie heads.. I could probably use my stamped steel rockers also, correct?

Sure can ... all the production valve train is usable if the original O.E.M. pieces are not worn-out.
Getting the exact correct lifter pre-load could require a different length pushrod, if the block or heads are milled a lot.

Cost was a lot more money and it just didn't run as well years ago when I built one with D3 heads and using a carburetor intake and early truck exhausts.
It didn't pull near as good however, Wide Open Throttle acceleration with no trailer was great. That endeavor was a real education.

Thank you... I'll post results when I'm done . Driving characteristics, how it goes and fuel mileage. Figure it should be able to equal or exceed the performance of the new 7.3 gassers

I have used these on the stock rockers, on the older heads.

https://www.summitracing.com/parts/fms-m-6529-a302?seid=srese1&gclid=Cj0KCQiAq5meBhCyARIsAJrtdr4F-wQ6LaVv1v_VkziHBwTQ0WXgFHljQd52fjNcKkkt1sH1EWCFg38aAm8NEALw_wcB

supervel45 wrote:I have used these on the stock rockers, on the older heads.

https://www.summitracing.com/parts/fms-m-6529-a302?seid=srese1&gclid=Cj0KCQiAq5meBhCyARIsAJrtdr4F-wQ6LaVv1v_VkziHBwTQ0WXgFHljQd52fjNcKkkt1sH1EWCFg38aAm8NEALw_wcB

Thanks you! I'll order a couple sets