vortec heads+hotcam+1976 350?

Will the hot cam kit work in my 1976 355 w/ vortec heads? Vortec heads casting # is 10239906,are these from a  305 or 350?I heard this casting # is not as good as #12558062,but the car they are on now runs great w/ just a mild cam.  

HAMRDOWN,

You have to be very careful with the OEM Vortec heads, due to the limits of the valve springs.  In order to get the full "Hot Cam" effect, 1.6 rocker arms are recommended, this combination pushes the valve lift beyond the recommended limit. You can have the valve pockets machined and use "conical" valve springs, or purchase new vortec heads that have already been prepped for larger lifts. These heads are available, I believe from a company called "Pace Performance Parts", or you could call up "Edelbrock" and have them send you a pair of their "E-TEC" cylinder heads- they offer two different sizes, the 170's and the 200's, either would work very well with your proposed combo. If you do choose to use the Edelbrock version heads, be aware that they are aluminum, and will require head bolt washers between the head bolt and the aluminum head to prevent galling the heads. One more little piece of info is that the heads come with guideplates for the pushrods, which may be taken off and replaced with the supplied hardened washers, or it is recommended that hardened pushrods be used if the guideplates are used.

Hope this helps!

Chris

The "...906" head is just fine. The Vortec heads are limited to about .45 inch lift at the valve before you need to trim the top of the guide and adjust the spring.

The HOT cam does not fit your block, it's a factory roller and needs an 87-up roller block that has the machining for the thrust plate. You can get a factory roller cam into an older block by making a spacer to fill the step in the front of the cam. This provides a bearing surface for the cam gear of the roller cam timing set you would need to use. By the time you spend that time and money you may just as well have bought an after market roller cam. The other place you'll have problems is the lifters, the 76 block will require aftermarket roller lifters as it has none of the provisions necessary to mount factory lifters. That is the lifter bores are not tall enough to keep the factory lifter in alignment and oiled, and there is nothing for the "spider" which holds the alignment bars onto the tops of the lifters to mount to.