Both the 289 and 302 rods are too small for the 3/8" bolts but you can ream them for the ARP SBC 11/32" bolts that are just enough better than 5/16" bolts that they will take a lot more rpm. I spun a 350 HP 289 to 7500 rpm for over a year before I sold it to a friend who ran it for several years after that.
The 302's rods were the same from 68 to 1991. In 91 or 92, Ford revised the rods to either an F1SE or F2TE. (I've seen both numbers) The pre 91's all had the C8OE rods.
You can swap the rods, as long as you use a Boss 302 pin height piston (1.55) The rods are only .060 difference in length.
id goten the rods and pistons out of a motor that i got for cheap. it had bad rings. the pistons were dome pistons so i elected to use them in the motor i built for my mav. it was at the machine shop that the owner there said that they were 289 hi po rods. its possible that over sized bolts were put in and that was what he was refering to. either way i know i do have 3/8s rod bolts so i do feel confident that they are not going to brake.
If you play around with enough blocks and find one that has the higher deck height, you CAN use 289/boss rods with 1.600 Compression height. Keep in mind that most 302's with stock length rods and stock CH pistons have the pistons down in the hole by .015-.020". Some of the mid 70's 302s had a slightly taller deck height...not much taller...but with the right unmolested block and 289 rods with 302 pistons you can get away with it. Keep in mind that the pistons will be out of the hole slightly but that is fine as long as you check all your clearances I've done it...mocked up a 302 with 289 rods and stock '86 flat tops (no valve reliefs). Pistons were out by I think about .010" but again, that's not a big problem. Makes for good compression and makes your quench distance about .032 with the normal .042" thick gaskets. Also consider that 289 rods are a little heavier so you'll have to rebalance most likely. No big deal. Put a pair of 2V cleveland heads on it and you'd almost have a poor man's boss 302. Almost.
Yeah, I don't think he knew what he meant. 289 rods and 1.60 pop ups with 302 crank would put you somewhere like 18:1 compression... Better hope the exhaust valve has no more than .200" gross lift, or they're gonna meet.
