Capt Ken

Getting ready to change the oil. PO transplanted an early '80s 350 crate into my '73. Does this engine still have the flat tappets?

toobroketoretire

Yes, it wasn't until 1987 when roller cams first got used in the Corvettes. There is the possibility the previous owner installed a retrofit roller cam and lifters in it but you would still use a conventional oil in it.

BEVO76

For what its worth I run Valvoline VR1 10w30 with ZDDP even though I have a full roller. Hard to beat the protection of ZDDP regardless of what cam is in the engine. No cats with the ZDDP additive though.

BEVO76

Also heavily debating making the switch from Valvoline VR1 to AMSOIL Z Rod oil. However, both are very good in my opinion. You will have to order AMSOIL, but the VR1 you can pick up at O'Reillys any day of the week. Finally, not sure what filter your going to use but I wont put anything but a Wix on my car.

jb78L-82

Higher ZDDP levels can be used with Catalytic converters but will hasten the demise of the cat faster than lower ZDDP oils which is primarily the reason that the EPA lowered ZDDP levels in Mass market oils-really a non issue in a catted C3 (why would you unless forced by the emissions ****'s) since the cats will still last a loooong time with a high ZDDP oil. Maybe not the federal requirement of 100,000 miles at a minimum but certainly longer than most of us drive these cars..more crazy laws. I used a high ZDDP oil in my DD 2001 Grand prix for years...cat is going on 180,000 miles...Hmmmm!

Mobil 1 filters are generally considered one of the best oil filters out there but they are pricey. Not sure what NAPA charges for WIX filters which are very good but you can buy Mobil 1 oil filters which I use in all my cars for about $10 with free shipping on Amazon Prime.

In my Retro Roller cammed L-82 355 with a Howards cam (.525/.525 lift), I use Mobil 1 0W-40 European Formula with 1,000 PPM ZDDP...can't beat the price for this group IV PAO ester synthetic at Walmart @ $26 for a 5qt container if you can find it on the shelves (only Mobil 1 0W-40 and 5W-50 Porsche specified are true Group IV synthetics)...other Mobil 1 weights are group III+ conventional oils. Not sure about Valvoline VR-1 being a true synthetic (most US oils are group III+-highly refined dino oil and allowed in the US only to be called a synthetic). Amzoil is a true synthetic, no question.

70ZZ3 96LT4

I have been using Shell Rotella for years in my 1985 Corvette and it still has the original cat.

BEVO76

VR1 is conventional not synthetic. Correction you can run cats with ZDDP, my bad. What I meant to say is that it doesnt work well in newer engines fine in SBC Gen I.

ykf7b0

Havoline 10w30 with a few ounces of Lucas zinc additive for my 76 Vortec head L-48.

vette_jim

NAPA Gold filters $5.99 last week. 1" taller than Mobil1 which I use also. Thought I would try NAPA to see if it helps oil pressure although M1 has one of the best filtration results. Swithing to VR1 from Mobil1 15/50.

jb78L-82

I used Mobil 1 15W-50 with 1,200/1,300 ZDDP for years in my stock L-82 engine...now rebuilt with a roller cam I use Mobil 1 0W-40 European Formula (True Group IV synthetic, 1000/1100 ZDDP, Approved by every major German Manufacturer for their engines that require a special additive package and a true synthetic oil). Interesting stats here:

https://mobiloil.com/~/media/amer/us...pecs-guide.pdf

vette_jim

Good info., I don't find 0W40 on the shelf here.

7t9l82

I've been using VR-1 synthetic but I have an 8 qt system and had to go to Oriely and 2 auto zones to get that much. Probably go to amzoil this time have a dealer in my church.

fishslayer143

Using conventional oil after break-in is foolish in my opinion... Synthetics are so far ahead in lubrication and protection, double or triples the change interval, and probably will double engine life too, and Amsoil makes one with Zinc for your flat tappet cams.too. . Why spend $5000 + on a performance engine and then put $2 /qt oil in it?

jb78L-82

Capt Ken

Got some time....watching the paper for the right oil to go on sale. I only put maybe a 1000 miles a year on the car, easy street driving no racing. It does an mildly upgraded cam in it, so the oil matters.

Kubs

Just to add to some of the info here, if you are going to use a higher zinc oil make sure it is designed around those levels. Never use a zinc additive. It does not always add protection and can sometimes reduce the effectiveness off the zinc already in the oil. It is best to use an oil designed around higher levels of zinc.

Also, for those using VR-1, it is a Racing oil and does not have the proper detergents for cleaning moisture and sludge protection. Race car change oil more often so its not necessary. Using it on the street is a bad idea.

I would highly recommend AMSOIL Z-Rod, or AMSOIL Premium Protection 10W-40 (Z-Rod only comes in 30 and 50 weight).

68post

I bought mine off of Amazon, and the price was right too, (and free shipping) !

jb78L-82

Correct about "racing" oil not appropriate for street driving with a long drain interval but probably fine for limited miles cars like a C3 if you drive less than 3,000 miles per year although I probably would not go that long...maybe 2,000 miles...

I think that Amsoil High ZDDP oil is a great choice for a synthetic for flat tappet cammed engines as well as Royal Purple HPS (high Zinc) 5W-30. Mobil 1 0W-40 European Formula (1,000/1,100 ZDDP) is slightly low for a flat tappet cam, in my opinion, and I only use it in my roller cammed cars (which is al my other cars including my 94 5.0 liter Mustang GT convertible) and my 78 L-82 355 with a retro fit roller cam....easily the best value for a true synthetic oil on the market @ $5.50 a quart @ Walmart when purchased in the 5 Qt jug.