273 302 318 340 build

Both my 69 FSM and 84 FSM have 318 rods weighing 726 grams. Nothing on the pin weights. Another difference I noticed is the piston pin bore dia on con rod. 69 ff is 1.027"-1.039" where the 84 pressfit is .9819"-.9834. I havent tore the 70 down yet to confirm. But the rod #'s on the 70 = FF style.
Im trying to wrap my head around the piston pin dliemna.
All the pistons that I can afford are the press fit style and 0.984" OD. SOOOO that means I cant use the 70 rods due to the diameter difference.
So now like "theham" mentioned that difference in conrod diameter and pin style has thrown a real wrench into things and is starting to confuse the **** outta me. I know there is a science to this and am starting to appreciate what goes into engine building BUT this was supposed to be a simple small block budget build and didnt think there would be this many hurdles to overcome on a 318 build.
Hope to teardown 70 318 in the next week.
2 318's later and a friggin stuffed garage, I got a call about a 340 shortblock that is apparently good to go. I have complete freshened x heads on the shelf and LD340, then definitely use 270S cam from the 273.
So unless I find 318 pistons within my budget, the 340 shortblock to purchase will be about the same as the 318 pistons, rings and machine work on 302 heads???
I wouldnt be stressed out if I had another 500 sq ft of garage space, but that aint the case. As it is now theres 3 engines in the shop im tripping over and seriously contemplating the 340 shortblock. I have a "rebuilt" 904 to go in the cuda, whether its 318 or 340.
Im still open to suggestions here, and "theham" I thank you for sharing your knowledge and time. When you can I would appreciate the "how to" on DIY balancing. Im not sure if I go that route, thus the title of this thread....covers a little bit of every sbm LOL
Yep, figgered that was what you would find. Campbell Enterprises often is lower than Summit and Jegs on KB's. But that is still are a LOT pricier than the 526AP's, and the lighter KB's means re-balance....although that would be cheaper to do that since it will require taking weight off of the crank, not adding it on. That is why I keep poking all that info at you about drilling out pins and such....so you can bypass the re-balance cost.

You are good with working on parts so there IS a way to get the re-balance cost waaaay down: you do the rods and pistons yourself, and compute the bobweight and hand that bobweight to the shop to just balance the crank to your bobweight. (I'd be happy to explain how that works.)

I would not be scared to use the '83 cast crank.... all I can find is that they are good for 400 HP or more and you won't be anywhere near there with the lower port flow of the 302's, even if you put in the larger valves.

please,..carry on an explain!