Big block 455 - suitable engine oil

[tom.r]

It can be used in the big block engine GM (Buick Riviera ) 455 cui , Year 1970: MOPAR oil 10W -30 API SN ILSAC GF-5 ?

[bob k. mando]

the easy answer is just get Shell Rotella 15w-40 diesel oil ( more detergents and zinc than modern gasoline engine formulations but still reduced from 70s formulations ) or some other reputable diesel oil.

biggest thing is zinc ( or ZDDP ) concentration.

you can also get zinc oil additives.

most of the reason for the modern oil specs is concern for the catalytic convertors ( or Diesel Particulate Filters ) which is why a lot of those metals are being phased out of the lube and fuel liquids.

your 1970 is pre-catalytic convertor so it's not something you're concerned about.

[tom.r]

.....so it is also possible variant of use of the above new oil MOPAR API SN and adding additive zinc ? (ZDDP aditivum) ?

[bob k. mando]

that should be fine, yes.

[tom.r]

thank you very much for your advice

[LARRY70GS]

Adding a ZDDP additive to SN oil may not be the best answer. Modern detergent content in the SN oils is antagonistic to the ZDDP. I use Brad Penn or Joe Gibbs Driven oils. They have the proper mix of ZDDP and detergent for older cars.