ps374

What gives the L71 35 more horses since the carbs are the same as the L68? Was the L68 really Nessary with the L36 only lacking 10 horses? And is the hood scoop on the 427 able to be make functional without cutting or drilling.

BLee

There are some big differences. Like compression, cam, and the heads. The carbs, the displacement and overall appearance are the same but the internals are a lot different. There was a functional scoop planned for the L-71 but it was dropped. It's in the assembly manual.

BL

knight37128

Biggest difference is the heads.

Oval port heads are (maybe) $200.

1967 rectangle port heads are $10,000 (or more).

rjhuhn

All of the comparison articles I've read in Hot Rod/ Car Craft and such seem to conclude that modern, pocket ported, large valve oval ports will equal or out perform rectangular heads at street RPMs, but give up HP on the top end. Any real world, seat of the pants experiences?

67pete

Hmmm, let's see...3" wide bias belted tires and 400+hp.

GUSTO14

Lets not forget the solid lifter cam in the L71 verses the hydraulic in the L68. Remember the L68 used the same cam as the L36. The L71’s three carbs also did deliver better fuel economy in daily driving, since it was essentially a 2-barrel engine until the secondaries opened.

There was also undoubtedly pressure on Chevrolet to step up to the plate with it's own Tri-Power for enthusiasts to compete with Pontiac and Chrysler Tri-Power offerings.

GUSTO

knight37128

Modern "pocket ported" large valve heads?

Junk. We don't drive big blocks to get groceries. That's what small blocks are for.