[jhill2001ss]

My father has a 70 chevelle with a rebuilt ls6 big block in it and wants to change the oil over to synthetic, what would you guys recommend as far as oil goes. It is all original. Also what brand fluids for the tranny (4-speed) and differential. Any help would be greatly appreciated.

 

[rianbechtold]

If it's rebuilt to stock specs you'll find alot of people advising to stay away from synthetics. It should have a solid flat tappet cam in it and the newer oils have reduced zinc and phosphorus (anti-wear additives) in them. Most synthetics that are going to have the correct anti-wear package are going to be pretty expensive (I believe redline has some but its $15 a quart I think)

For the drivetrain however, there are some highly recommended brands out there. I like using royal purple gl-5 75w90 in rear ends. As far as the 4 speed goes, make sure whatever fluid you go with has a gl-4 and not gl-5 rating. The gl-5 rating will eat away at the soft metal parts inside the trans.

 

[72sbc427]

x2 Royal Purple.

 

[jhill2001ss]

ok what do you recommend for oil (not synthetic). the car is completely original

 

[BillK]

John,

Any good name brand 10w30 should be fine as long as you use a zddp additive. I have had good luck with Valvoline over the years. For a real nice car where the oil probably wont be changed but once a year, I would spend the extra money for either the Joe Gibbs racing Hot Rod oil, which is a synthetic, or RedLine etc. Personally I have Mobil 1 in everything I own and have not had any problems with flat tappet cams even though the cam in my S-10 and my Wife's Riviera probably do not have much spring pressure S-10 has 260k on it and Riviera has 160k, both with 5W30 Mobil one since the first oil change.

 

[jhill2001ss]

ok I just ordered the joe gibbs hot rod oil 10w-30, what kind of oil filter should i use and where do i get one?

 

[rianbechtold]

ok I just ordered the joe gibbs hot rod oil 10w-30, what kind of oil filter should i use and where do i get one?

You can get the premium wix brand at napa, I forgot the name but they are good. Also, I believe the Napa gold is the premium wix brand, do a search on Napa Gold on this site to verify that.