Not exactly sure of the year range, but I do have a set from a 67 318 I tore down a while ago.
I know for certain that by 70 they got away from those valve reliefs.
I think it could be a great combination. Stock pistons, normally .130 down the hole end up at .005 up.
If you can keep the block at .010 over max, you could source out a set of 66-69 (I think) pistons that have valve reliefs already cast in place.
Small bore would rock with a set of 1.88 360...
You're way over thinking this. Piston weight is an entirely different thing than rod weight...and big end rod weight is entirely different than small end.
Stick the pistons in there and don't give it a second thought.
Going beyond the factory recommended overbore limit ( generally .060) exponentially reduces rigidity at the deck surface.
Block that are designed for sleeves have their head bolts anchored to the spine of the block and not the deck, directly.
I gas welded up the chambers on a Slant head a few years ago, but canned the project before I had it machined down..ended up tossing it on the scrap pile. I do plan on welding up another for a current project.
Welding onto cast iron is actually pretty easy..it's repairing cracks when things...
The only 318 blocks that will take that .090 cut and not flinch are the 66-down Polys.
They are still pretty cheap and plentiful, and STRONG. High nickle castings that weigh a good 30 pounds more than the later LA blocks.
There is no HP "gain" to reversing piston offset, but the actual effects are very noticeable.
By reversing the offset, you are leaning the rod into the direction of crankshaft rotation earlier in the cycle giving peak cylinder pressure a bit more leverage to work the reciprocating assembly...
Beware swapping water pumps from early late style.
Everything around them is different.
The early pump is shorter, so none of the pulleys, brackets or accessories will interchange.
I could agree with that.
The thing about these threads that always frosts my cupcakes, is the general bad name that points get.
I have run them in everything from daily driver to Top Fuel dragster and have had nothing but success with them.
Hotter coils, CDIs and MSDs are all great things, and...
https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.hotrod.com/articles/ccrp-9812-ignition-performance-test/amp/&ved=0ahUKEwjMhq3Ikv_WAhVGYiYKHSN0Dn0QFggzMAM&usg=AOvVaw2HTIoeuGERL8JHz8-VmXAA&cf=1
Once again, for the hundredth time, I refer back to this test...which mirrors my own...
This could very well be the dumbest thing I've read all year.
I've been building engines from Top Fuel down for 40 years.
Under 600 or so horsepower, there is zero benefit to running forged over cast in a Mopar.
Junk cast cranks are a Ford/Chevy thing.
Swap in the crank and rods from the 318, and don't concern yourself with balancing the thing.
Yes, there is a weight difference with the pistons, but because it is located so far from the rotating assembly it will not effect anything
Limited use car, leave it out.
For something that sees daily traffic and all, you want it in there.
Without the slinger, after a few thousand miles, you'll see an oil film building around the front of the engine. Over time, it can get real gnarly
I had this exact thing happen when I welded up the advance slots and breaker plate on a stock distributor once.
I was rushing through the job, and welded the plate in a too far advanced position.
As a result, it tried to kick back every time I tried to start it, regardless of where I positioned...
Lose it, and at the same time, add a vapor separator style fuel filter to your gas line, close to the carb.
Plumb the oriface nipple of that to the steel line vacated by the canister and you'll get rid of 95% of any vapor lock issues you may have.
Not exactly applicable to the discussion, but this was my solution to fan/water pump drag on the Slant Dart that I recently built.
Drag car, and so weight was more important to me than anything else.
Car has no alternator, so I used the stock W/P pulley, and a belt that I was able to...