390 FE Synthetic or Conventional oil?

[dirtydrc]

I have a new 390. Had a shop install it. Re-manufactured 390 long block from Mabbco Motors, RV cam. Broken in, had it's break-in oil changed already (last year). I'd like to change the oil this season. Is there any issue with synthetic, or stay with conventional oil?

[Jacksdad]

Now you've done it - you asked the oil question. This should be fun...

[DuckRyder]

Here is what the company has to say about ti.

https://www.mabbcomotors.com/oil-recommendations

Though I might not entirely agree, it could be prudent to follow these instructions if the engine is under warranty.

It could be prudent even if it is out of warranty depending on some technicals of the remanufacture/rebuild which you may or may not know.

With a flat tappet cam I might be tempted to run a HDEO or HM oil.

[colnago]

Now you've done it - you asked the oil question. This should be fun...

Don't you know it! This is worse than "should I run my distributor to ported or manifold vacuum?"

I just dropped a rebuilt in the old girl last fall. I used Comp Cams for break-in, then changed it out for fresh Comp Cams oil. After 1000 miles, I went to Valvoline VR-1 synthetic racing oil, because of the high zinc content (side note: it has a blue tinge to it!). I'm not sure what I'll use next, but I'll probably stick with synthetic.

Joseph

[Ohiotinkerer]

Now you've done it - you asked the oil question. This should be fun...

This is what happened last time I got involved in that......

http://www.fordification.com/forum/view ... 96#p731496