Head's & Cranks

[vigman]

Around the 76-80 years...

Are all the cranks forged in Corvettes?

Or is it engine specific L-48 Cast L-82 Forged?

Same with the heads...

Which FACTORY heads are 64 cc or were they all bigger..lo-po smogified engines.

And

Are all the heads & cranks about the same and it was the cam that made the difference in output?

What about the head casting anything to look for ( or stay away from )?

Mike

 

[Tom73]

Mike,
I cannot speak specificly to the later years but for the 73 year L48 and L82 differences, check out this page on my web site: http://www.corvetteforum.net/c3/vette73/compair.htm

The L82 used the heavy duty parts, forged crank, Alum. impact extruded pistons, and 4-bolt mains. It also had higher compression and big valve heads. And, of course, the cam was much wilder (as as the 350ci/350hp engine of '69).

The power differences come from the cam, the higher compression, and the bigger valves. Not a whole lot of differences there. But the L82 had the heavy duty parts, which did not add to hp but did add to engine liveability under hard driving conditions.

tom...

 

[Twin_Turbo]

All 76-82's use the 462624 76cc 1,94x1,5 valved smog heads (open chamber) Stay away from these heads, they're lightweight thin castings and are very prone to cracking!

The L82's use a forged crank, L48, L81 & L83 use a cast crank.

L82 has pink rods, others have X-rods.

L82 & L83 have 464664 forged L82 TRW 2 relief flat top pistons, others use cast 4 valve relief pistons.

L82 is 4 bolt, others are 2 bolt. The 2 bolt blocks have a higher alloy content and are once converted to splayed stronger than a regular 4 bolt!

Marck

 

[Jack]

My 71's L48 350 came with cast crank (c/n 3932442) , 2-bolt block (c/n 3970010), 76cc small valve heads (c/n 3973487), cast pistons (as opposed to impact extruded aka forged), iron intake w/Qjet, low-performance hyd cam.
JACK

 

[vigman]

Heads 101

These are the heads 333882 what chambers are on it? 64 or 76cc? and what kinda valves.

My engine book list's a TON of applications for this head...

And where do you find this secret info... short of popping em off?


Mike

 

[Tom73]

The 333882 heads were 76cc.

This from www.mortec.com

tom...

 

[vigman]

Thank You!

Been busy as a bee....... forgot about this!

Another chunk of info to put these heads in the junk bin.

Mike