New to the forum, thank you for having me! I am starting a build on a 302 GMC for a close friend, his late father started this by collecting parts for quite a while but never started to actually build the engine. I have allot of experience building engines, just not this one. Looking for any tips that might be helpful, most notably Camshaft choices and rocker choices. We are working with a Fontana head, I assume they take OE rockers? He has two NOS short blocks. We will Probably have pistons made, how do the rods hold up in these things? Any info would be helpful and appreciated. Thanks again, Jack
That engine has many threads here and doing a search function will yield a treasure trove of information. I am sure folks like @302GMC will chime in soon. Welcome to the HAMB from Virginia.
Google assist.... https://egge.com/product/gmc-truck-302-56-59/ Check Egge out for pistons as well. Those Jimmy's had some torque. Hope that helps. PS - I miss my Buddy Lou below who passed about 9-10 years ago.. Yes, that is a highly hopped up 302 Jimmy 6 that sounded like a hive of angry hornets that Lou started in 2nd gear because of the torque launch. Was top Eliminator at Desmoines Drag Strip Multiple Years late 50's/ early 60's. Miss Lou. Good Guy.
A lot of guys run 1.94 and 1.6 small block Chevrolet valves with .100 longer than stock stems. I don't think that you'll have any problems with the connecting rods so long as they are in good shape to start with, as they're pretty rugged. Arias can make you any configuration of forged piston you want; of course, they're not going to be cheap.
Big Nick died seven years ago, Arias facility was closed down, name bought and folded into C-P Carillo brands. Not saying they're not still good pistons, just check around for alternatives. jack vines
I’m surprised it wouldn’t have the roller rockers Joe made for all of the ones he reproduced. If it’s an original Tom Skinner stock rockers will work but you might need to bend them a little to lineup perfectly with the valve tip. Joe’s has a spacer under the rocker cover to contain the oil. A stock cast iron or military steel cam can be reground by any reputable cam grinder. Some one like Schneider in San Diego or Elgin in Central California are best for someone doing what you are looking for. They both can make recommendations for your application. If you have a roller cam great.. they are unobtainable along with lifters for the most part. Pistons will be flat top and down in the cylinder to make the compression you want. I use the compression calculator on the Keith Black site to do this. A “Best” head gasket is .050” thick and 4.140”diameter and the protruding valves are usually 7 cc. You play with the formula until you find what you want. Since the engine has a 4” stroke a 1/4” or .250” down in-the cylinder will be approx 16-1 and 1/2” down 8-1. You get the idea. I have used Arias, Ross, and CP and they are all excellent. Stock rods are 7” and very stout. The pin needs to be .990. I’ve set countless records at Bonneville using them before I had custom longer ones made. They are just an air pump…a heavy one, and for the most part fun but getting more expensive to build and having fewer parts available with searches needed…good luck have fun and don’t be in a hurry….. PS: Nick Arias III (Justin) works for CP..
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