Rokker

I bought a 1971 F100 with a 390, C6 and N/A rear end ratio. Seems to be somewhere in the low to mid 3`s. Tires are street tires 265/60-15.

It has a Holley 2v carb that flows 280cfm and points
stock iron intake
Engine seems all stock with stock manifolds.

I`ll be using this truck around town, a few trips here and there, moving lightweight stuff around. I wan`t more power and double the mpg
Cruising steady 50mph I`m at 9 mpg.

It`ll break the tires loose from start at half pedal, and giving it full it stops pulling around 3500rpm (I don`t have a tach).
I`m blaming this on the tiny weenie carb, and wan`t to change it out to a q-jet on a performer rpm intake. While the intake is off I also wan`t to change out the cam. So I wan`t some ideas on which cam to choose. I`d like to keep as much of the valvetrain as possible. I won` t be turning any rpm`s, max around 5000rpm.

I`d like to buy:

Used q-jet on evilbay, rebuild it and thune with apt mixture screw
Buying an rpm intake (using adapter to spread bore)
adequate cam (need advise for a stomp puller with great fuel economy, low end torque and can hang on to 5000 rpm)
I`m thinking somewhere around 210/215-220 @ 0.50, maximum lift of what the stock valvetrain can handle, 110 lsa.

What is the most lift I can run with stock valvetrain ?
Is there any chance my heads and cr are ok for performance around 300hp and 400 ft/lbs ? I`m thinking I have around 200hp as it is now, with GREAT idle and low end performance.
Where can I find numbers on the heads to find out if they are any good.

The engine is OLD and rusty, but doesn`t have any noise to it, doesn`t use oil and runs smooth. So I`m going to try and up the power a bit.

Also curious about my cr ratio, won`t be changing pistons as that is too much work without doing a complete overhaul. Milling the heads is a possibility, but not sure if I will gain much without doing a full port job on the heads, and that is a little more work than what I`m willing to put into this project.

Also looking for a set of full lenght headers, but willing to use the manifolds until I find a good deal locally.

Am I on the right track with this ?

Rokker

I've written to a few cam companies this is what I got so far:

COMP cams:
33-234-4
Specs:
1,000-5,200 rpm
Duration at 050 inch Lift:212 int./219 exh.
Valve Lift with Factory Rocker Arm Ratio:0.487 int./0.493 exh
Lobe Separation (degrees):110
Hydraulic-Strong torque through low and mid-range. Good idle.

Crane:
13404
1400-4800
210/210 int/ex
Lift: 0.516 int./0.516 exh.
Lsa: 110
Good low and mid range torque, Smooth idle, daily usage, light towing, off road, 2200 - 2700 cruise RPM, 8.5 to 10.0 compression ratio advised.

I like both of them specs wise. I'm curious about how much lift a stock 390 can handle. And I've heard the 390 heads have really poor flowing exhaust ports so that maken me like the COMP cams more. But also heard there COMP cams have a bad reputation with cams going flat.. *
Let me know if anyone have tried one of these cams.

Rokker

110 views and no replies ? Am I asking the wrong questions or is it because i mentioned the q-word?? Lol

Rokker

A guy locally is selling a offenhauser 360 single plane intake.
I know a single plane isn`t the best at all for what I wan`t to do. BUT it is very cheap, 80 dollars, and being what it is I might opt for a touch more cam too.
How do you think it will work ? They say it`s good from 2000 and up, but since 390 is quite a bit of engine I`m thinking it might run good from 18-1900rpm.
Should I buy it ?

chipset

For what it's worth a 390 gets 10 MPG at any speed under any conditions. That engine
will not do 5000 RPM and stay together unless there are serious bottom end mods.
A 360 manifold feeds a 360 not a 390. Your better off with a 460. Comes with a 4V and
more torque. stock. Your C6 transmission will not fit the 460. I think your diff will stay
together if you keep your foot out of it. For what you want to do with your 390 your
wasting your money if you want to haul light stuff. If you want to put that money into it
take it to the track. You also have to change your suspension if you want to hold up a
460. You can get all the power and gas mileage out of a 460 without spending a dime
on your 390. You can get 1200 H.P. out of a 460 if you go nuts. I've built hundreds of
engines in my time. There are better ones out there than the 390. Don't get me wrong
they are a good engine. I ran one at the strip. Turned high elevens. Modified stock. street legal. 6 M.P.G. 1967 Mustang. Let me know exactly what you decide and i might be able to help.

Rokker

You're joking right ??

chipset

ROKKER. I'm too old for this. Been there done that. I don't joke. My first job was rebuilding
1932 - 53 ford flatheads at 16 years old in a rebuild shop. A 390 is a good engine but
limited. 332 - 352- 390. same block. FE. ( Ford - Edsel ). 429 - 460 same block but not a
FE. As i said before if you need help and you think i can help let me know. I'll do what i can