I am in the process of building my motor, i have bought everything that i need so far except for connecting rods, clutch and my flywheel. I am having some troulbe deciding which rods to get, i was told that the GM 5.7 powdered connecting rods that i was going to get would not work unless i did some grinding? I did not think it would be a problem using the 5.7 rods verse the 5.56 ones. So now i am looking at EAGLE "SIR" lightweight 5.7 rods, they are 570 grams and have ARP wav Lok 3/8 bolts. I just want to know for sure if these will fit without any grinding if anyone has any thoughts let me know... I am using a Comp Cams Extreme Energy 268 series cam. Here is a pic of the eagle rods i am thinking about gettting:

 

i'd buy rods that use bolts instead of nuts and i'd fill the bottom inch or so of the block. there is always a chance you'll have to grind the bottom of the cylinders and the oil pan rail.

 

I doubt you'll get away using 5.7 rods w/out grinding. They way I did mine, is I bought the rods already ground so they dont hit the cam. Works fine

 

I used the Eagle SIR rods you pictured on a 3.75" stroke and had to grind a hair off the top outer edge of the #2 and #6 rod bolts (They hit the cam)

Also the nuts were too close for comfort (They passed through no problem, but a sheet of paper couldn't be slid between the nuts and bore bottoms.

Instead of taking the material off the block I just indexed the rod nuts and ground it off the nut. (Don't worry, it's not enough to cause any structural probs)

You should be OK, unless you have core shift or your block is alot different. Mine was a 4 bolt "010" 1973 350 block.

Just do a trial fit with some old bearings/and no rings on the pistons. Good luck.. Of course you can always get capscrew rods which will make it easier..