My 350 with bore .60 over, will replace with brand new piston and cam, Just wonder what oil weight I should run on my carb 350 ? I heard good thing about 10w/40 on these engine, but im very confident on running dino oil 10w/30 and change every 3k miles. btw should i stay with napa gold filter or ac delco ? thanks

 

Both filters are good just don't run a fram filter. After I built my 355 I started running Mobil 1 10W30 Full synthetic. Better protection and better performance. I personally only run Delco oil filters though.

 

this engine is fresh rebuild, what are good breaking in perior and oil change service ? Im running 5w/30 pennzoils with ac delco. or should I run stray 30 weight for first 10 min then 10w/30 for first 500 miles, then 10w/30 PP ? help me how to break in engine ?

 

I change mine around every 3000 even though i've heard with the full synthetic you can usually go around 5-6K without an oil change. It also depends on how you drive. If you beat on it daily I would change it as close to 3000 as possible if not sooner. As far as oil go's I highly recommend mobil whether it be the sythintic or non synthetic. I had a gm engineer recommend it and havn't had a problem with it. It doesn't gum up like some of the others i have seen. I would also say not to beat on it to much for the first 500 miles. If you are going to beat on it after the break in you should give it a little rough housing for the last 150 miles or so just no full throttle stuff till after the 500 mile break in. Also make sure you change the oil right after the 500 miles to get rid of the assembly lube that will be mixed in during break in.

 

Would help to know where you were on the planet. Changes things a bit on the recommendation.

traight 30w on break-in if it's a flat tappet. And a significant break in time with conventional oils. Then synthetics.

FYI- Strong rumors have it that the regular Mobil1 is now not a true PAO synthetic anymore. Only their extended version is, the regular mobil1 has only ~20% PAO of it's basestock.

 

I heard that running a full synth could promote leaks. I was under the impression that running convention but changing it per the schedule was a-ok, and in fact what the engine was designed to run on. I've got my engine to stop leaking, so I'm not opposed to trying it with a synth, but I don't know.

 

my friend help me build this car, I dont know alot thing that he list yet, I will ask him and will post up here.

 

Amazing how long it takes to get old information and wives' tales out of the system.

Synthetic doesn't promote leaks. That was an issue with Mobil 1 back when it came out in 1975 and into the early 80's, but was never an issue with other synthetics like AMSOIL, and hasn't been a problem with Mobil 1 for a couple of decades.

Changing a conventional petroleum-based oil regularly and often is necessary, but it isn't sufficient to prevent wear and deposits that you won't get with a quality synthetic, even with extended drain intervals.

Anyway, this wasn't a type of oil question, it was a weight of oil question. If rebuilt to stock specs, 10W-30 or 5W-30 will be fine. Using 10W-40 won't gain anything, won't reduce wear, but will suck up more power.