76chevyK10

whats up guys? I'm new to the forum and I was just looking for maybe a little input on the motor im putting together. what im trying to do is get the best I can get out of this block without boring the motor. I have a 76 chevy k10 shortbox, I found a vortec 7400 in a local scrap yard so I have big dreams for this motor. my current set up is edelbrock 750 cfm carb, edelbrock 7164 aluminum intake, comp cam, 1966 427 corvette oval port closed chamber heads casting # 3904390 rated at 98.4cc, mallory billet distributor, headers and a th 400 tranny. The only thing I'm worried about is the fact that this big block is a vortec motor, so I'm kinda worried that it would work naturally with my carburator. would I have any problems with this Gen VI engine block? and if not, whats the best way to maybe get a guess of how much hp and torque gains I may have? Hope to get some responses soon. thanks

James B.

iTrader: (1)

The block will accept Mark-IV and Gen-V/VI heads, the difference is the cooling flow. Current heads flow parallel and the ones you've got are series. Your 396/427 heads have about the same size combustion chamber as the L29 heads, 98 vs 99cc.
The block has a roller cam in it, so when you select a cam choose one appropriate for a Gen-VI engine set up with the factory thrust plate. The have a smaller bolt circle for the cam sprocket and a stepped nose for the thrust plate.
Next to the oil filter you'll notice cooler line ports built into the casting. You can't use these unless you can find an adapter that includes the bypass block-off that extends into the port. Just plug them both with 3/8" NPT and you'll be fine to use a standard cooler adapter sandwich under the filter.
If you desire to change the harmonic dampener keep in mind that this is an externally balanced engine and that the Vortec dampener has a different shaft depth due to the reluctor ring inside the timing cover. You can run a standard-depth dampener/balancer if you pop the timing cover and remove the reluctor ring.
The flex plate has the large 6-bolt converter circle.
GM does make a dual-pattern flexplate which would accommodate a smaller performance converter but it's balanced for the 454 and 502 crate engines which have forged cranks. The conterweight is about an ounce different - worth taking both flexplates to a machine shop to have balance-matched.
Don't spin the bottom end past 5800. NOTHING in there is light-weight and intended to make RPM.