S code vs. RPM

[Doug Comer]

I read a little about an S code intake being better for towing than an Edelbrock performer RPM. I'm building a 410 for my highboy right now and have both intakes. After reading the post I'm a little unsure which to use . My truck has 4.10 rear gears and I'm running 285's for tires wich are around 33" tall. This is my daily driver and I use it to tow as well. All opinions welcome. Thanks Doug

[Doug Comer]

Anyone have an opinion? Doug

[fordman]

an uninformed opinion would be the edlebrock would be better. but that from a uninformed source.

[DuckRyder]

What is the RPM range of the cam?

[Doug Comer]

Fordman thanks.
Duckryder. I haven't choose the cam yet . Maybe I'm getting the cart before the horse. Just made me stop and think if I should consider using the S code instead of the RPM. Doug

[mrtleavitt]

I would go with the Edelbrock. I've used Edelbrock for a while now and have been very satisfied, plenty of power to pull anything.

[DuckRyder]

The "S" intake is not a hi performance intake, that is not to say it is a bad intake but for making power the RPM will out perform it. With the right cam and compression the S might make superior tourque to the RPM up to say 2000 RPM, but it will run out of steam between 4000 and 5000.

I'd say pick your cam, then your intake...

[My427stang]

I'd say it runs out of steam at closer to 4000.

If it were me, I wouldnt run the S code, not worth the weight to have a loss most everywhere in the curve, especially with a 4.11 gear.

The RPM works great, another option would be a CJ iron intake, but they bring big dollars nowadays

[Doug Comer]

Guys thanks for all your opinions. I think I'm going to stick with the RPM. I had read the post about the S code and started to second guess. Thanks again Doug

[rubiranch]

not worth the weight

Does 50 lbs really make that much difference on a 5000 pound truck?

[Jake11]

If you got it, run it. It works fine on a truck. It'll pull to 5K. Shop around and find a deal on a high rise while you
drive it. Jake

[My427stang]

not worth the weight

Does 50 lbs really make that much difference on a 5000 pound truck?

It does if you ever have to take it off

A comment to Jake though, it wont pull to 5000, the S code is a pig. The T code might pull a smidge higher, but they are both poor manifolds.

I would run an S code or T code if I had no other 4 barrel manifold, although I will say I would pick one in a heartbeat over an SP2P, so there is one worse, LOL, and I may even pick it before an Offy dual-port, but thats about it.

They have neither the port size, shape, or plenum size to support more than about 4000-4500 rpm.

With that being said, if the thing will never see over 3-4 grand, then hey, run whatever stock intake, but if you are putting any work into a 390, go with a real intake

[Jake11]

You better have a talk with my "S" manifold. It don't know it can't do that. Maybee it's in the wrench that works on
it? LOL Jake

[averagef250]

You're comparing apples to oranges. The RPM and S iron intakes are very different.

Why in the world would you want a 6500 RPM intake with no exhaust crossover in a tow vehicle 6000 pound truck?

FE's makes gobs of torque. For even the heaviest towing with a 428 stroke you will not be turning the engine over 3500 RPM ever unless you just want to wind the nuts out of it for no reason. If you have a 4 speed you will be able to accelerate any load up a grade above 1800 or so RPM with a common sense cam choice that takes advantage of these engine's long stroke and big torque potential. To keep the engine above 1800 with 4.10 gears and 33" tires you won't need to turn over 3500 ever.

If you run the RPM you will lose any useful torque below 2200 or so, atleast that's my experience. I wholeheartedly agree with Jake that the S will pull to 5000, but it shines very well in the idle-4000 range. In this area, it will stomp the snot out of the same engine with an RPM intake. In the real world an engine in a 4 speed heavy truck that can put loads of low end to the ground will outpull any high RPM peaky power thinks-it's-a-race-engine thing you can put together. Use an intake that's suited for what you use the truck for. I would never run the RPM on the street in a heavy truck unless I had a really big inch (428+) engine and low gears.

For a cam, idle to 4500 works great like the crane 901. Less compression is more with towing 8.5:1, maybe up to 9.5:1, but the more static compression you run the more you'll be pinging pulling a heavy load.

[Jake11]

YEEAAAH! Somebody with common sense. Cool. You hit it right on. A F250 ain't a racehorse. You could make it into
one, but get out yer wallet. If ya have to actually haul a ton of stuff, and it will handle a ton and a 1/4, torque at
1800 and up to 3500 is what makes it walk right past those chebrolays on a grade. The 390 is just taking a walk while
those cute little 350's are screaming and getting ready pound the rod bearings out or poof a head gasket. A 454 will
match a 390. If it's running good.

Yes there's nothing wrong with the "S" cept you need a crane to sit it on the motor. I use my cherry picker.
Before you tighten the bolts, put the distributor in so it lines up ok. Throw the cork things in the trash and
use a bead of silicone on the ends. You'll be glad you did. Jake