on the topic of synthetic oil

[carpenter547]

sorry i know totally lame nOOb question *wow can't belive i used that word*

any way got some unused quarts *5* of royal purple laying around do to happy circumstances beyond my control i have nothing to put them in but my truck 71 390.


i know our trucks were build before synthetic oil was around and as such weren't built for them but do they get benefits from using it any way.

right now i use supertech from wallmart.10-30. the royal purple is also 10-30. any advantage?

[gregamorton]

You need to flush your oil good to get it all out. I run royal purple in my kubota tractor and it does not use a drop of oil now. It seem to have alfull blowby before so I decided to try it out. Also with the synthetic it seems to leak more if gaskets are bad.

[cdeal28078]

I tried a full synthetic in my 71 back when it had a 351w in it and I couldn't stand the smell. Seemed like every time I drove it I could smell the oil real strong. Crazy sounding I know. I figure it was leaking out of all the gaskets but not to the point of leaking yet.
I run Motorcraft in my cars and am happy with that product. Run the filter also. I am not sure if it is full or semi-senthetic
clint