72 250 6 cyl cam?

[72SB]

Is the stock cam flat tappet hydraulic or full roller hydraulic??

[Palf70Step]

Flat tappet. I honestly don't know of any roller cam setups. Well at least I didn't when I built mine 3 years ago.

[72SB]

yeah I assumed since IIRC 88?? was when GM went to full roller

Given the low zinc content in todays conventional oil, I may add some Rislone zinc additive. Not sure what was used by PO's. Motor has about 116k mi on it but runs quiet as a mouse

with that said I used conventional 10-30 in my flat tapped hydraulic 327 motor without issues

[Palf70Step]

For a new cam I would definitely run high zinc oil (Valvoline Racing) plus additive ( I used GM breakin additive or Lucas oil brand) . That is what I do on all mine for breakin. It might be an overkill, but It stinks to loose a cam on break in for a few dollars extra on lubricants. Then I normally end up using the Rotella T4 diesel oil after the initial break in period

[72SB]

I use break in oil even on full roller cam motors (Valvoline VR1) on first start and 500 mi

While I have not had issues on motors with just flat tappet hydraulic cams using todays conventional 10-30 oils (read motors that have a good deal of milage on them)....I am going to add zinc additive to conventional oil in the 72 250. Its the original motor, I assume untouched, but todays oils just don't have the zinc content they did pre CAT motors

[AussieinNC]

Originally Posted by Palf70Step

Flat tappet. I honestly don't know of any roller cam setups. Well at least I didn't when I built mine 3 years ago.

There are roller cams and kits available for 250 - 292 engines....

https://www.12bolt.com/store/p196/Bi...292_Chevy.html

Most "stock" flat cams are perfect for street use....just remember the Zinc additive unless you are using Valvoline VR oil....