318 engine swap!

[AJ/FormS]

I have found also, that 340 heads on stock teener equals dog at low rpms. You will need a cam to take advantage of the heads, and then it gets even doggier down low.
On the other hand,teener heads on a 340, works real good down low, and with a teener cam, has tons of giddy-up.Tons and tons and then it's over

 

[273]

I think it boils down to what you want.
I believe the drop in CR is the bigger deal.
But if you want over 300 hp there's little choices.

But from the sound of what the OP wants I think 318 heads are fine for this application.

I'd still go the 360 head route with 9:1 CR
For the added 30-40 and sure it will be at an higher rpm but were probably talking a peak of 5500 instead of 5000.

 

[nm9stheham]

318s have plenty of torque down low. Dogs up top though. After a bit of driving newer trucks it doesn't take long to see what it is you want, what's lacking- and it's not torque under 1000RPM. Under 1000RPM my truck could idle on a hill and with a touch of gas bring a car up the hill with it. Pulled more cars off trailers than on them with it, and often in ice- even pulled a truck with a boat attached up a muddy hill. All with a little stock 318, tall gears, and big tires. A 360, steeper gears, or shorter tires wouldn't have done better because it did excellent. On hills? Never lacked for torque with the low compression teen and 4bbl, loaded or not. Never gave trouble. But a dog up top, no doubt about that. Fewer V8 motors in the last 2 decades have less power up top than old LA 318s.

Just get it running well. Make sure the motor going into it is in good shape. 360 heads would bolt on, you'd see a gain in power over the 318 heads. Gears, daily driver, and fuel mileage don't go together.

Not trying to be too argumentative...just trying to pull all the pieces together.

That torque down low is due to the short duration cam usable to maintain usable torque used with the low compression 318 LA pistons ... and that same cam's low lift is a big cause of the breathing problems up on the top end. The power gain with the open chamber 360 heads is gonna all be up top, and CR is gonna drop even more. Then if you increase the cam's duration to get even better high RPM breathing and use big open chamber heads with that CR drop, the bottom end is just gonna drop out. The 318 low CR is a setup that gives you one or the other, but not both: low end torque only or high end poop only.

Those newer truck engines that you refer to no doubt have huge ports compared to LA ports PLUS they have good CR. So they will have good RPM performance from bottom to top, with it all enhanced by the better profiles of a roller cam. IMHO, those new engines can't be used a basis for comparison with setting up an LA318.

And good pulling in slick conditions is usually a sign of low torque.... makes it hard to spin the tires.... which was made even lower with big tires and tall gearing. So that does not sound like proof of high torque... it sounds like just the opposite. I don't think pulling loads up steep, muddy hills is not what the OP is looking for.

 

[Infecteddog]

Those newer truck engines that you refer to no doubt have huge ports compared to LA ports PLUS they have good CR. So they will have good RPM performance from bottom to top, with it all enhanced by the better profiles of a roller cam. IMHO, those new engines can't be used a basis for comparison with setting up an LA318.

Very true, but compared to an old teen or 360, your 4.6/4.7/5.3 are gutless on the bottom even though they're quicker once moving. The Ford 10s never really impressed me much on the low-end either. CR varies, anywhere from 9.2 to 11ish, few of them are really that relevant though. Also- the 360s back when the 318s got 360 heads had the same low, I think sometimes even lower CR.

And good pulling in slick conditions is usually a sign of low torque.... makes it hard to spin the tires.... which was made even lower with big tires and tall gearing. So that does not sound like proof of high torque... it sounds like just the opposite. I don't think pulling loads up steep, muddy hills is not what the OP is looking for.

Not typically smart to put power on quick enough to spin in a low traction scenario if you're pulling something. The other bit- that's my point. A driver car doesn't need to be able to pull 4500lbs, drag a car up an embankment, or anything of that nature. The obsession to keep power down for something even a light duty pickup can spare is a bit ridiculous in my mind.

I donoo. Years ago I had the same solid cam in a 318 with 340 J heads, and it wasn't all that impressive. The last summer I had the 67 together it had a nice low miles 318 with "all stock" except that same cam, Performer intake and headers. 318 heads. It ran pretty impressive.

I agree I don't think the big ports are a problem, but the compression drop, in my opinion, IS a problem

4bbl and headers with the J heads? You lose a bit of compression, a small cam won't take much advantage of them. Totally stock with what cam? The performer's pretty weak compared to the stock intake but headers help, and most of your late '84-up motors have more compression than the older ones. Any big drivability problems usually put a decent bit of power out the window, to the point that a good running motor that doesn't make a lot of power can feel tons stronger because it's actually able to efficiently use its power range fully and smoothly. With a small cam all your gains will be, so a handful of little things can make more difference than something like a head swap even without losing any CR while picking up power.