Hey guys got a quick question here. I am just about to do my initial start up/break in on my 383 sbc build. What oil would you guys recommend?? ( I'm assuming 10W30 but what manufacturer would you recommend or does it really matter) I was thinking of going with Royal Purple, heard nothing but good things about their oil. Thanks for any advice and input here.

Keith

i'm a Valvoline guy

If the cam is a flat tappet you have to use a oil that still has the called for additives to keep the cam from going flat, if not it will go flat in a hurry. Dont waste good money on royal purple on start up, after you break in the cam you will have to drain the oil and change the filter, why waste the cash on the good stuff only to drain it out 30 minutes later?
I believe it was valvoline racing oil that still has the needed ingrediants.
Also on thought, do not run sythetic oil until the engine is broken in, if you use it right off the rings wont seat. I would use the valvoline racing oil until the engine had at least 2500 miles on it or better, then I would go over to synthetic.

You can also use any of the oils made for big Diesel engines. They come with the high Zinc & Phosphorous additives that help with cam breakin. And there much cheaper than Racing Oil. You need to drain&change after cam breakin.
Chevron Rotella, Mobil, Delco etc.

Don't use synthetic oil for the initial startup or the first 1500-3000 miles.

Shane

I'm just before firing my 300 six and went through the same mind-numbing exercises of determining what oil to use. I've used Castrol GTX with good success for many years, so decided to use GTX diesel oil 15-40 along with 10 ounces of this.....
http://www.sfrcorp.com/product/9

A friend of mine who has his PhD in chemistry recommended it to me. He wrote to the company and got all the straight scoop on this product. It is supposed to contain a good percentage of ZDDP, the extreme pressure lubricant which has been removed from conventional oils. Since I'm breaking in a new flat tappet cam in the motor, I wanted all the protection I could get. One quart delivered to my front door cost me $37.37. I'm using 2 ounces per quart of oil for startup, then 1 ounce per quart for subsequent oil changes.

bunch of the stock car guys here swear by john deer tractor oil 30 wt for break-in i dunno?... ive always used rotella and a bottle of comp cams cam lube. with good sucess. have used castrol for many a years with good luck to.

use brad penn straight 30wt oil,and a little additive comp break in or eos,after that use 10w30 for the next few thousand miles then you can switch to royal purple