Hello! I have a 85 flareside and wanna know what i should do to the 300 to make it more powerful?

 

You can put the standard hop-up parts on it, like a new intake, small 4 bbl carb, etc. But speed parts for the six are very expensive compared to the v8's. And your results may not be that dramatic.

It's better to appreciate the old 300 six for what it is, a over built low horsepower work horse that will work for you all day, and get you there and back reliably. It's not a race engine.

 

Make sure it's running properly, that the timing is right, etc, before wanting to improve it.

 

My 300 will do just about anything I ask of it.





Just not in a hurry.

 

All due respect to the 6, but.......

Yank it out and swap in a V8.

 

It is at it's best for low end grunt in stock form. I've warmed up a couple of them for fun but the mileage goes to heck and the power band moves up so you have to rev it more. The best improvement you can make is doing a good clean up port job on the head.
For ease of tunability, I would get rid of the feedback system and put it back to 83 or earlier spec.

 

I'm not ocnvinced. Looks like 120 HP and 223 ft/lbs. That's horrible, my 460 probably makes more torque at idle. Heck even my torqueless diesel probably makes more torque at idle.

Port the head, install late model split exhaust into duals or a proper header, 4v intake and Holley 600, pistons for more compression, aftermarket cam. Probably cost as much or more than building a small block. Small block costs only slightly less than building a 385 series. If you want power just find yourself a 460 and swap it in, it's a bolt in deal aside form oil filter relocation to clear the crossmember. Not worth the hassle or expense of making a tiny engine perform in a chassis that easily accommodates a proper engine.

 

I had that same set up, 390 Holley and 260 comp cam with a ZF 5 speed and 4.10 gears in a 3/4 2wd. No head porting. It really wasn't that much better than stock and never got much over 12 mpg, if ever. Plus you had to wind it another 500 rpms over a stock engine in every gear to have any torque. I drove it a lot of years but wouldn't waste my time and money to do it again. A lot of money spent for a small and questionable return. Also remember the efi duals or headers eliminate the heated manifold and that really cripples the mileage because now fuel is more likely to puddle or not atomize good in the intake. Some guys using the aluminum intake build a plate to go on the underside that circulates cooland and claim that does help the mileage issue a little. I never tried one.

 

all true what has been said. all true.
the 300 responds to careful tune and....a FISH carb!!!!
use the efi dual exhaust
the FISH has soiled britches of unwary drivers.
also, cool the oil,
also turn the cam straight up. degree it properly, rolling the retard out of it
the U turn head design is your limiting factor. a fish atomizes better thus fewer issues with irregular fueling.

play with plug heat ranges especially on 1 and 6.

truly amazing power can be had with....a turbo!! pushing air, rather than that long engine pulling air. bout 10 pounds boost please, water injection and you will scoot.get real fancy with propane at 115 octane and no more drop out....

keep everything cool

the clifford -offy -390- header-weber: is a waste of time/money/energy/and gas.