US300hp

I have a 1969 Corvette 350cu/350hp that I am rebuilding. I want to build it to the original specs of an L46. The block is original bored .30 over with original crank .10 under. What is the correct cam to use? The heads were not correct so I am looking for original spec heads also. What would the specs on these be and what compression should I be looking to achieve, This car will be a street drivin, pump gas, nice day car but some good 350 hp feel will be nice too! Thanks for all your help.

Gordonm

The original 350/350 motors used small combustion chamber heads. 64cc heads were used and the motor had 11 to 1 cmpression. Not to friendly with todays pump gas. My suggestion would be if you want to use the original heads go with some pistons that will lower the comp ratio to a max of 10 to 1 with the iron heads. Use a more modern cam that will bleed of some of the compression to keep you out of detonation and still give you good power. All this is internal so you can't see it but will make it more friendly to use with todays gas.
The head casting numbers are
3927187, 3927187, 3947041 depending on when the car was made. If you are a numbers guy you also have to match up the casting date.

stingr69

You can use "186" heads. The chambers are 64cc's. The original "962" cam is still available from GM or from Crane as part of their "Blue Racer" line.

As for pistons, you can go with some flat tops and get the compression down to the lower 10's and it will run fine on pump gas. I have that cam running 10.4 C/R and it runs well for me.

-Mark.

US300hp

Thanks Guys. I have flat top pistons I am using. What is the Duration and Lift of the 962 cam? I was looking at Comp cams and didn't see the equivalent. What type of range to lower the compression a bit is good? Are moly rings better to go with than stock also? Thanks again

stingr69

Jegs has the exact copy of the GM piece as a Crane/Blue Racer part number 270-WG1170K

Do not try to look at those lift or duration numbers and try to make any comparisons to other cams. They aren't close enough to match up with anything from the aftermarket. The "962" cam has a slightly noticeable idle with a soft bottom end RPM and pulls strong to 6000 RPM. It will pull a little higher if you have decent flow and good valvesprings.


A Comp 270H is probably a close in application aftermarket grind that will work with the 10:1 or so compression if you want to go with something other than the GM part.


-Mark.

US300hp

Mark
I looked in Jegs and all I see is 270-WG11...03K, 59K, and 73K. Is the one you recommend the 03K? Thanks alot
Andrew

stingr69

270 is the vendor number I think. Do a search on "WG1170K" and it should come up fine.

-Mark.

J-Vette1

Stick to an engine combination and gears that has proven to work for someone and you will save a lot of grief and $$. Taking advice on a cam from one person, gears from another, and compression from a third will be the ideal Frankenstein .. Good luck! (I'm currently building mine to specs between an L46 and L82 for a nice street driver (they were the same engine but the L82 had lower compression) ....

J-Vette1

Any idea if the L46 used stock valve springs? I am building one, and want to keep the springs as light as the cam will allow, so it lasts as long as possible

cv67

Might wanna click the "new thread" to the left of the page and ask your question..this thread is many years old

HeadsU.P.

Please start a new thread so we know which person we are talking to. Eleven yrs ago?