Here's my engine build 306 mexican shortblock with forged rods and pistons (9to1), moly rings, steel main girdle all ARP hardware, fluidampner, double roller t-chain with TFS stage 2 cam, moroso 1 piece pushrods, TFS 1.7 roller rockers, TFS R heads box stock, TFS R intake box stock
along with D1SC ProCharger set at 16psi
Which grade oil should I use?

 

what exactly makes your engine "mexican"?


lol

 

The choice of lube oil is as much based on the design of the engine as bearing clearance.The oil has to get to the bearings as soon as possible upon start-up so I would use 10w30.Maybe even as low as 5w30??
I would avoid synthetics for the first 500 miles but after that you can switch to a full synthetic.

 

open up www.google.com and type in 306 mexican block. Good luck on your research

 

I use regular old Castrol GTX 5w30 in my 306..