Ok, I resealed the heads and now no leaks. I used brad penn break-in oil and its time to change that. I have ten quarts of mobil 1 15w-50 synthetic from a friend to use, or what I normally use is Valvoline VR1 20W-50 racing oil. Which should I use or does it matter. I prefer to stay with the Valvoline though. The engine will see track time. Thanks.

Brad Penn 15w40... but that's not on your list, is it?

I would use the VR1. If you use the Mobil 1 I would add a zinc additive. Or Brad Penn is a good choice as noted above.

If this is a new engine do not use the Mobil one till you have at least 5k miles on it.

Go to napa and get some 10-40 VR1 , the 20 50 is too heavy and not needed.

great, thanks all.

I've used Mobil One 15w50 in my street/strip hemi since I built it...well, after the break in period was done. I like the VR1 Valvoline also.

Rotella 15/40 is what I use.

Chip, what was your break in period , Dan Costello is the one that told me about going 5k first.

I start w/ the conventional VR1 Valvoline oil. Ran it for about 20 minutes or so in the shop and easing down the driveway (my driveway is 1/4 mile long), then changed the oil and filter (more VR1 conventional). Then ran it once at the track and put maybe 50 HARD street miles on it before I put synthetic in it. I drive the snot out of em from the get go.

The hot new oil is JR1. Just look at how many cars were running it at Indy. A bunch of proven winners are displaying the decal. They sold out of their supply at Indy. It's only been out since the first of the year and has taken off like wildfire.

I know of several different pro racers sponsored by different major oil companys back in the mid 1970 to the late 1980s that had the sponsoring oil company decals on the car and would fill their sponors containers with Kendal GT oil in the shop from 55 gallons barrels they bought by the pallet loads, 6 top 10 barrels at at time BTW, to the OP, I use Valvoline petroleum based 5W20 WT in most of my rigs, race or street, except the 2006 Ram 3500 CTD 4whd , it gets Delo 400 15W40 wt diesel oil

I feel it's hard to pin down one specific oil weight, due to the combination of parts, clearances and vehicle application. The shop that built my deal (Tesar), has dyno'd a ton of different use powerplants, and is firmly in the Klotz camp. I use 10w40 Estorlin.