Fluid recommendations
 

Just about Got the wiring buttoned up this weekend and have a couple questions before I attempt to fire it up. Can I use regular Pennzoil 5w-30 to break in the engine without using the lead additive? Ive been told to use Dex Cool antifreeze only. Is this true and can anyone share some info?

4.8 stock rebuild

Thanks

Re: Fluid recommendations
 

Unless you have a completely sealed cooling system, which means basically using the factory surge tank and everything that goes along with it, I wouldn't use Dexcool. Using Dexcool in a system vented to the atmosphere will cause it to turn to mud anywhere it comes in contact with air, such as the vent hose near the radiator cap. I have personally seen it happen on my own vehicle, but never had a problem with the old fashioned green stuff.

Re: Fluid recommendations
 

So im good using regular ole prestone mixed with some water?

Re: Fluid recommendations
 

Yep, or you can run just RO water with an additive in summer (not for winter storage). I've run water, or regular green stuff in any vented system.

People will argue about oil all day (Kinda the idea behind Bob Is The Oil Guy's page) but for the most part you can run any 5w30 syn you want safely in an LS motor. There are certain arguments against Royal Purple due to its observed viscosity thinning and causing oil consumption. I've Run Pennzoil, Redline, Castrol, German Castrol, Valvoline, and a few other brands that are made by those already named.

Re: Fluid recommendations
 

Ive heard a few arguments against synthetic for the first 1000 miles. I use Pennzoil unltra synthetic 5w30 in my daily driver. You think I'm ok with that also or should I go mineral oil then switch to synthetic?

Re: Fluid recommendations
 

Since your talking about break-in, yea. You don't need to necessarily buy a "break in oil" though. FWIW, Napa branded oil is just Valvoline so if you need to go through a few jugs, its a cheap decent dino oil.

Re: Fluid recommendations
 

Ok thanks!

Re: Fluid recommendations
 

I have always used the Amsoil OE oil in my LS and now in my LT, they also have break in oil as well.
Don’t contaminate your engine with regular oil, use the synthetic break in oil and then the 5w30 full synthetic.

Re: Fluid recommendations
 

Flat tappet cam‘s in the old motors needed a break in oil with zinc but motors with roller cams it is not necessary but would not start out with A synthetic oil you want to let the rings have time to Seat properly Clyde brought up using a synthetic break in oil honestly I did not know they made a synthetic break in oil have always Used a non-synthetic for break-in and then switch to synthetic

Re: Fluid recommendations
 

im going to check into synthetic break in oil. May go with that otherwise I will use Pennzoil straight 30 weight then switch to Pennzoil synthetic once the time comes.

Re: Fluid recommendations
 

Re: Fluid recommendations
 

That looks like what ill need!