Wow those heads have great flow numbers.

 

I'm anxious to put mine to work.

 

They are very good numbers and when compared to the 062 Vortec better in some respects. The low lift flow is exceptional. So much so, that it might change the camshaft spec when considered. But the intake valve is very small and as such, one way one of thinking is that the engine is still under-valved and the tight LSA might be helpful.



It's important to note that these flow numbers aren't necessarily from the same bench, so consider the results with that in mind. Personally I find it difficult to believe that the 059's outperform the 062's at higher lifts.

 

Yes, it's a compilation from varying sources. Useful, but not exact.

And it is interesting how strong the 059 exhaust side numbers are Vs the 062.

On the intake side, the 059 does retain a vestigial "ramp" like the stock L03, though much smaller in comparison. That would explain the better at 0.1, damn near as good through 0.3, and not too shabby to .05 numbers, despite the smaller valve. Despised as it may be, the swirl port technology DOES work at enhancing low lift cylinder filling.

Based on the results GM Powertrain got out of the jump from TBI era 305/350 to Vortec 305/350, I've always asserted that the Vortec "treatment" was just as effective, if not more so, on the 305. But as in most threads, as soon as you say 305, most readers tune out.

 

If the 062s are Hecho en Mexico they flow like crap compared to the production heads of the 90s and into the early 2000s. I had 059s and 062s as well as canadian 906s on the same flow bench.
The 059s outflowed the mexico 062s by a few cfm across the board on the intake side and almost exactly the same on the exhaust. The 906s flowed a little better on the exhaust and alot better on the intake. The 062s flowed about 218 at 0.400 then port stalled and flowed 215 at .450. The 906s flowed about 5-10 higher up to .400 then at .450-.500 jumped to 235-240 cfm. The difference in power was very noticeable as well between the lower mileage OEM 350 and the Hecho en Mexico crate engine junk.

 

I know the 350 we put 059s on ran its a$$ off. Never knew they flowed that good I just figured it was the higher compression. Im anxious to see what this guys combo does I bet it makes great power.

 

I am guessing more than my Tahoe. The Tahoe made 270 hp and 280 tq at the wheels. L30 with stock 502 heads upgraded to Comp 787 retainers and Pac 1218 springs, Lunati 218/218 flat tappet cam with Rhoads lifters and a set of 1.6 rockers. BBK equal length shorties and 2.5" exhaust from the headers to the muffler with thunderbolt 2.5" high flow cats. Ported vortec truck lower intake and a Volant CAI. Tuner black box with stock 23 lb/hr injectors. I had electric fans and a 25% underdrive crank pulley on it.