Cylinder head decision for 318

@toolmanmike
Great idea!
here's my winter engine from year 2000 to 2005
___________________
I know what I would do.
Oh, wait, I already did it a couple of times.
Stock 1974 LA318 short block with a 2bbl 360 cam, a bit more valve spring, a small-port CI 4bbl intake, a TQ, TTIs and full-length 3" duals, and 3.91s is a mountain of fun. I ran it with both a manual trans and a 904/2800, and an A998/2.74 low gear with 3.55s. I also tried the A833od box. And one time I ran it with 4.30s, but that was ridiculous,lol.
My favorite combo was the "close-ratio A904/2800/and believe it or not 3.55s/ with a TF-2 kit. With this, I could put it into third very early and floor it. Imagine a very long slow pull in third gear, with the Dynomax 3in/3out mufflers screaming. What a blast. Anybody remember a 67 Pontiac 2+2, 283/2speed PG, that hit 85 in first gear? Hyup a friend in hi-school had one, and that was the sound I would occasionally gravitate to.

My second favorite combo was with the A833-od box,4.30s,and the GVod bolted onto the back, used as a splitter.
The gears were 3.09/2.41-1.67/1.30-1.00/.78od-.54dod Hyup 7 gears.
Top of first-over was 40ish
and she hit 60@5350 in second.
and 65=1920 heehee.
the starter gear was 3.09x4.30=13.29 what a blast. First was done at 30, then hit the electric shift and 1od took her to 40. Then into second, then 2-od and hit 65mph@4500, just about right on for that 2bbl-360 cam. Count 'em up; that's 4 ratios to 65mph,lol. Ridiculous fun, in my 3650# 68 Barracuda(me in it.)
In the end, that low-compression 318 did not like the wide ratios of the A833od box. I replaced it with a Commando-box,so I didn't HAVE to split gears ALL the friggen time. The ratios are;
3.09/2.41-1.92/1.50,-1.40/1.09-1.00/.78..... 8 gears but
Typically shifted as a 4+1,or mostly
3.09-1.92-1.40-1.09-.78, giving me a short 4th. and
occasionally shifted; 3.09-2.41-1.92-1.50 to hit 60mph=4800; now we're talking.
I lost dod (double overdrive) so now 65=2700. I slowed down a bit,lol. Eventually the 4.30s gave way to 3.91s. Then 3.55s, and with those;60mph was 5100 in 1.92, the third selected ratio; close enough, and well worth it for 65=2240.

So the point is this;
The bottom-end of that 74 318 was lazy to start with, even with a freshening. And the 360 cam didn't make it any better.
But the 4.30s and 3.09 low-gear, perked it right up.
The mid range of a low-cylinder pressure smogger-teen is not impressive either, but 3 or 4 gears, from zero to 60/65, solved that.
And the 360-2bbl cam pushed the top-end up about 400 or perhaps 500 rpm higher, solving the top-end lay-down, with a lil help from the 850cfm, Carter-rated 4bbl.
And finally;the GVod brought the 3.55s back to 2.77 for cruising with.
IMO, that is how to deal with a low-compression 318.

If I had it to do over, I would just put decent pistons into it, and install a SFT cam, to maintain the pressure and VP, and call it done.

And that goes double when using an automatic.
When I used the 2800 and the A998(close-ratio)/loc-up, it acted like a 5-speed.
First gear with the multiplier in the TC, acts like a 4.41 at zero mph, then rapidly upshifts to about 3.43 at shift-rpm. Then in second it declines to ~1.74 towards shift rpm. then in third, it declines towards 1.1, and finally in loc-up, she hits 1.00 . Count 'em;
4.41 diminishing to 3.43-1.74-1.1-1.00..... Now add the 3.91s

17.24-13.41-6.90-4.30-3.91,Compare that to my manual combo, with 4.30s
13.29- 8.26- 6.02-4.30-3.35; as I "normally" use it with the GVod. Or
.........10.97-6.82-4.97-3.55-2.77 my final combo3.55s.
It's really hard to fault the TF-automatic.

What I learned was that;
for a streeter,it is easily possible to have too many gears, and that 3 of them to 60mph is lots enough.
And too much gear in first just goes to tirespin, lot and lots of it. But if you can learn to get your 3.91/904/2800 out of the gate, it's gonna make a mad-dash to 60 that surprised the heck out of me. So much so, that in 2005, I was in no hurry to re-install my summer combo.

Now, having said all that; how about the A500?
With it's .69overdrive, you can run just about any rear gear you want to and that's great cuz to hit 60 optimally at say 5200, requires a 6.64 ratio, which in 1.54 second gear is 4.30s. The .69od lets you run 65=2400 in loc-up, with those.
Now yer all set up for a 4900/5000 power-peak; which is about a 220*@.050 cam in a 318. Badaboom. Make it a solid, and you get to keep some cylinder pressure. Make it a 108 or less LSA. and you can get the headers to work for you. Since it's a loc-up, Ima thinking minimum 3400stall, but with a starter gear of 11.78, just about any stall will work, cuz you are not gonna need much help to get moving. The only reason to use more than 2800 is for the 1-2 split where the ratio is .56, so out-shifting first at 5200, gets you 2920 going into second, and the nose is gonna drop like a rock. A 3400 here, is gonna perk the shift right up.
Now you could use that smoggerteen right outta the box, 8/1 Scr and all.
And! And because you now have a starter of 11.78 with a 3400(lol) stall, that 318 whiplash is gonna be right at home in there.
If I was planning a smoggerteen combo, that is how I would do it;namely with an A500/4.30s. I mean still not the Whiplash mind you,lol.

But as to my engine?
I would use a stock magnum with a short-ramp, hi-lift Solid-lifter, 220ish @.050 sorta like this;
Static compression ratio of 9.4:1.
Ica of 55*, sealevel.
Effective stroke is 2.76 inches.
Your dynamic compression ratio is 7.99:1 .
Your dynamic cranking pressure is 163.28 PSI
V/P (Volume to Pressure Index) is 130

Between the 2400@65, and the 120 or so degrees of power-extraction, I just know I can pull some nice mpgs out of that Magnum headed combo.
With an LA318, it would only a bit more work (pistons and closed chamber heads).
I could be shopping for a solid lifter cam of 220/[email protected] or so, and after lash of;
258/262/106+0/ 55* Ica/125* comp/123 extraction/48* olap.