I have a 1981 F250 4x4 truck with a 300-6 and T18.

How can I get more power out of it?

Carb, exhaust, 5spd Mazda? Any suggestions?

Thanks, rusty nail.

 

I fixed your grammar and spelling.

What gear ratio is in your axles?

A 5-speed transmission is for highway gas mileage, not low-end power.

 

Also to add, the 300 does not like to be revved up like a v8 does.

The 300 has very little high end power. So if you are revving it up thinking you will get more responce, you will find in reality the opposite is true.

Keeping it in the 1200-2500 range will give you the best performance on a stock 300 in good shape.

 

I am nearing the completion of a performance build on my 300 I-6. I've made a lot of modifications and dropped a fair bit of cash on it, but I'm pretty happy with the results. I probably have around 180 horsepower now... maybe it doesn't sound like a lot, but it came from the factory with around 120!

Anyways, a short list of my upgrades include:

• bottom end rebuild with higher compression pistons and ARP hardware (not necessary if yours are in good shape, but mine needed a rebuild)
• Offenhauser dual-plane intake
• Hedmann full-length header (a real POS... it was $200, I would recommend EFI exhaust manifolds or if you wanna spend the big bucks and can find one, a Clifford header)
• Edelbrock 500 CFM Performer-series carb
• Comp 268H cam with new timing gear, lifters, pushrods, valve springs, retainers, locks
• DUI distributor (basically a GM HEI distributor)... a lot of guys run a Duraspark setup which is a lot cheaper (and you probably already have it). If you do, just put a better coil on it and do the typical maintenance on your distributor like the cap, rotor, and wires

Now, bear in mind that this list is very incomplete... there's lot of little things that you don't think about until you start working on it (unless you've done this stuff before). I would also recommend going with a smaller cam than the 268H. I like the way it sounds, and it pulls good, but you have to rev it up to about 1500 RPM before it really starts waking up. Now in a screamer V8 that's not a problem, but on my 300 I6 (which idles at 700 RPM), I have to rev it a little bit before it starts moving. BUT - it pulls hard up to about 4000 RPM and has plenty of power now. Good luck!

 

Reps to you for the honesty, Mark. As I read your post I thought "Oh no! Not a 268H in a 300! Too much cam, but how do I say that??" But, you did it for me.

I ran a Comp 252H in a 351W and it pulled hard from idle. And, I realize that you have 50 cubes/cylinder and I had 44, but 268 is a big jump from 252.

Rusty - I'd recommend downloading Comp's application and playing with it to see what cam you want. But, don't get too excited with the horsepower and torque #'s it produces as their head flow figures are way off - at least for a Ford head. However, the program will let you look at how their different cams develop power, and you are looking for your power to come in right off of idle.

 

thanks for the great info guys