Also got to looking at the connecting rods and the number on the side says 3418645 and as i search that number it bring up for a 318 and 340. Starting to think I have a mess on my hands here!!! Will those work in a 360?
He does have some conflicting information between the text, photos, and charts, but this is what makes the most sense:
What you have is the 3418645 Which was used in the 318 and 360 2 bbl engines which is a pressed fit wrist pin. The heavy duty rod was used in the 340 and 360 4 bbl's and was a full floating wrist pin.
If you use heavy duty rods in an engine originally equipped with light duty rods, you will change the balance of the engine. This balance can be as much as 100 grams.
If you choose this route, and they only recommend it if your engine is for heavy duty use, the crankshaft, vibration damper, and flywheel or flexplate must be balanced to the rods before you assemble the engine.
Translation -- Use the rods that you have. They will be fine for a street engine and you won't have to go through the trouble and expense of rebalancing. I've used them in 360's for street engine with no problems. I've converted 360 2 bbl engines to 4 bbl by only changing the carb and intake, and even a cam without changing to heavy duty rods.
You have another decision to make. Do you want to run new aftermarket rods or recondition the old ones. I will explain the pro's and con's of each one:
You can use new rods.
Pro's: They will be cheaper than reconditioning your old rods. They are new. You can choose to use press fit or floating wrist pins based on what pistons you choose.
Con: They do not have an oil squirt hole to oil the cylinder bores like the stock rods do.
Here's a link for new Eagle rods at Summit racing. Look at the 3rd and 4th on the list. One is for press fit pistons, and the other for floating pins for $260 - $280. Look into what Speed Pro pistons are available with each wrist pin style (pressed vs floating) before committing on the rods. You should be able to get a good set of 9.0 - 9.5 pistons for the 360 in pressed fit to match the press fit rods, I think that they make full floating pistons in 9.0 - 9.5 compression - you need to do your homework for that. Here's the summit link:
Pro's: They have the oil squirt hole to oil the cylinder bores. I like that. I haven't seen any data to prove that the engine can last as long without the squirt holes as it can with them. If it was there from the factory, there must be a reason for it. Believe me. The drill required to drill that hole is very small diameter and is prone to breaking. They have to keep stopping the operation and changing the drill bit when it breaks, which reduces output. If it wasn't needed, why would they go through all of the trouble to keep it. Chrysler could have saved alot of money to eliminate that, but didn't. I know how they test their engines before sending them to the public and I trust it.
It's common sense that the engine bores would have less wear with the oil squirting on them. Then the oil ring scrapes off any excess. It works!
Con's: It cost more (about $40). YOU WILL HAVE TO CHANGE THE ROD BOLTS TO USE THE OLD RODS.
The bolts stretch permanently every time that they are tightened. It's a small amount, typically .001" to .003" every time it is tightened and then loosened. You should not have more than 5 "clamp cycles" on a rod bolt. After 5 tightening cycles, they can be overstretched will lead to an early failure. When this happens, your engine will only be good for a boat anchor as the block, crank, and rods will be bent, twisted, and broken.
Now when they manufacture the engine, by the time that we get it, it will have at least two clamp cycles on it from the factory, maybe three if it was recycled and put into another engine. This leaves only two clamp cycles left. Now you have to plastic gauge the bearings before you assemble them to make sure that you have proper clearances. this takes one clamp cycle to run the Plastic gauge and then you have to check and clean it off of the bearing and crank. Then reassemble and torque them again. --->>> there's five You are at the limit. If anybody retorqued them before you, then they are over the limit. So you should change the rod bolts which will then require the rods to be reconditioned. Changing the rod bolts may cause the cap and rod to be misaligned, so you have to recondition the rods. My local machine shop charges $30 per rod x 8 = $240 per set + rod bolts at $70 which puts you at $310.
I like having the squirt holes, so I would pay the extra $40-$50 myself if it were my engine. It's worth it for the longer durability for having the oil on the bores.
Mancini has the high strength ARP replacement bolts listed for $70 and it looks like a less stronger set for $ . I would go with the ARP's for $70 Alex (Jeopardy reference - Alex Tribec)... Here is the link:
I would call Mancini Racing and see what speed pro pistons are available in the "C" package in 9.0 - 9.5 compression and find out what style wrist pin that they use and then make your decision on the rods. The Speed Pro's have a thicker piston skirt than the Keith Blacks and are closer to the stock piston weight and won't require balancing. I would recommend using a 9.0 - 9.5 compression Speed Pro piston with press fit pins and recondition the stock rods.