Does anyone know of a short block that has the factory 5/16" rod bolts in it that has seen some abuse. I am wanting to use a 90 5.0 ho bottom end with only 60,000 miles on it, until spring when I re ring/bearing and put 3/8 rod bolts in it. I am not sure how fast or how high of an rpm these 5/16" bolts will take. Thanks Steve
There has never been an issue with the stock rod bolts unless your reving past 7000 rpm on a regular basis. A hydraulic cammed engine won't go beyond 6500.
If you are planning to spray NOS on your stock motor, hopefully your rod bolts, as long as you don't get carried away you should be ok. Stock motor weren't really made with NOS in mind but they can hold up under some pressure. Good luck! Bossmav
Wanna bet LOL. Stock rod bolts are fine unless you're spinning heavy pistons up around 6500-7000 regularly. That being said, I spun a stock-rod engine over 8200 many, many times in the bracket mav before I switched to H-beams, and later the 351. Actually, a friend and I had burnout constests @ the races, he beat me (spun 9200, I only got it up to 9000 in the water box) but no failures. Wasn't making much power up that high, but it sure was fun!!!
I'd switch to good quailty rod bolts such as ARP just for the insurance. Its a lot cheaper than the alternative, should they fail. The 5/16 rod bolts are generally regarded as one of the 302s weaknesses along with the oil pump shaft, which is also marginal.
I have had the same set of milodon ( couldnt get ARP back then ) 5/16 rod bolts sinse 1989 . Probably have about 450+ passes on them , and the engine has been freshened every 100 passes . Shifted at 7500 and run thru the eyes at 6800 rpm Never seen cheesy NOS though . I do not recomend drilling out stock bolts to run 3/8 as you lose too much webbing , stock rods were broached . I dont really know much about rods made after 77 as I have never worked with them at all .
rod bolts 5/16 rod bolts are a disaster looking for a place to happen. They're weak and useage in anything going over 5000 rpms. Why do you think Ford used, what ended up on the Boss 302s, 3/8 rod bolts one the 289 HiPos. Get rid of them and use ARP or Milidon. Or get ready to do some serious rebuild.
