Your truck weighs ~ 5,000 lbs. You need torque. You need cubic inches. Go with a 360 for now. [Remember the balance issue]. Then build a stroker motor from the 318. You'll be happy.
5000 with 2 persons on board sounds about right, maybe it would be a bit either way.
5000/318=15.7 pounds per cubic inch which by itself doesn't sound that bad
until you remember, I think those 318s were rated at 150 hp.
5000/150= 33.3 pounds per horsepower . The lightest A-bodys ever produced,often had 170 slantys in them rated at 100hp. So by contrast, that would be
2700/100= 27pounds per hp; the difference being over 22%, in favor of the slanty.
So for the W200 to get to 27, would take 185 hp, or 35 hp more than what it was born with. Ok so 35 is doable with bolt-ons, to get to 27 pounds per hp. Yippee, no one ever bragged on their 65 Valiant 170 bring able to get out of it's own way.
Ok I get it you might want to keep the 318. So buy the heads, buy the cam,buy the 4bbl kit, and buy the headers and exhaust. Install it all, and be IDK, maybe $2000/2500 dollars poorer, and zero to 30 mph will be no faster than it is now, perhaps even slower, probably slower.
And the reason is simple, the loss of cylinder pressure and the later closing intake gave up even more pressure, and the cam moved the power up the rpm band some 400 to 800 rpm depending on how big a cam you install. The 4bbl doesn't gain ground until say 3500rpm, in first gear; how fast is that in your truck? and the new exhaust ain't worth much..... because it depends on the cam and 4 bbl.
So now you have this ~$2200 dollar hole you dug, and yur gonna have to spend another $1600 or more to get out of it, never mind being faster off the line. So now you go get the big TC and higher number street gears, that I mentioned in an earlier post.
And now your W200 jumps off the line and pukes, because the cam is too big, and there us just not enough cylinder pressure to sustain the acceleration.
So now yur really committed; you have spent nearly $4000, and all you got to show for it is a lil jump off the line.
So now out comes the engine for some new pistons and whatever machining will be required to make everything play nice together.Then you throw away that big street cam for a tight-lash solid lifter fast rate-of lift, torque-making cam; and finally after say $ 6000, you got more than a wet noodle.
When all is said and done;
You still have 5000/318=15.7 pounds per cube, and say 5000/250hp=20 pounds per hp, wait what? Yeah the 65 Valiant makes better than that with a 225, but hang on, you now have the TC and gears working for you, And with the new power starting at 3000/3500, maybe you can catch him in the zero to 60mph battle.
I'm trying to save you money, and disappointment, and headaches, and downtime. Since no matter what; yur gonna need a hi-stall and gears; wouldn't it make sense to start there?
Here is an easy test; I bet you have 235/75-15 or 16s on that truck. Take off those tires and borrow the shortest wheel-combo you can find, at least 20% shorter on there and that will make your truck feel like it has 20% more torque at take-off.
To simulate the TC, park on the steepest grade you can find, facing downhill of course, and hit it!, for three truck-lengths. Now imagine a new TC doing better than that on the level.
I stand behind my recommendation; You can start there or finish there, but you will get there sooner or later,
unless you get a bigger engine..........
Then maybe one or the other........
Then the one you missed.....
Cuz it's never enough,lol.
Where you will one day want to be is down at 12/1 or less pounds per hp, which being 5000/12=416 hp
Waitaminute, that number sounds kindof familiar; hm..........
