I have a 402 that I'm putting together and need help on picking out some top end stuff. I plan on using a set of cast iron heads that I have (#3964290) and a Comp Extreme Energy cam kit (XE268H). I would like to know if I can get by with a set of stamped rockers and stock pushrods? I'm planning a trip to Summit tomorrow and I'm trying put together a parts list. Also, I have a Edelbrock Preformer RPM (#7161) manifold for the oval port heads listed above and need intake gaskets but I'm confused on "open and blocked crossovers", can some explain what the difference is?

Thanks fo any help,
Clint

Look at the intake gaskets for open or blocked exhaust passages in the middle of the gaskets.

Normally, the passage is open so when the heat riser is closed, exhaust gas is routed across the intake base where the carb is mounted for carb warming and for divorced choke spring to heat up to open the choke as if a stock configuration carb, ie, Q-jet, is used. If headers are used, the heat riser is removed but the passage is still open.

If blocked gaslets are used, no holes provided, then an electric choke will have to be used, ie, Holley carb. There is a heat stove provided by the aftermarket to take the place of stock set-up if Q-jet is used, or used to be. Otherwise, a manual choke would need to be installed.

I just bought a set of these rockers, good for up to .600" lift:

http://www.crateenginedepot.com/store/Rocker-Arm-Kit-12368085-P139C25.aspx :D

Everett, Thanks for the reply. I will be using a Holley carb w/electric choke and headers, what is my best choice for the intake gasket? Thanks.

Clint

A friend of mine raced pro stock in the 1970 thru 76 time period. He had nothing but stamped stock rockers on any of his engines that he used from 1970 thru 74 before he switched to a roller cam. He was using many different cams,and started out with the stock ZL1-cam(.620 lift) and progessed to many of it's GM and General Kinetics variants. he shifted all of them at over 8000 rpm. He claimed that one up side was that the stock rockers were forgiving in the area of pushrod length. The large sled type contact pattern always hit the valve evenly even if the pushrod length was way off. Back then they ran 7/16" stock pushrods,but today you can do better with even budget 3/8" pushrods. My experiance is that you would gain very little or nothing with roller rockers in both terms of durabilty or performance.

Everett, Thanks for the reply. I will be using a Holley carb w/electric choke and headers, what is my best choice for the intake gasket? Thanks.

ClintYou should measure the ports of the head and manifold to see if they are the same size and buy accordingly. Once you buy a set, visually match the gasket to each mating surface, head & manifold, to ensure a good seal between both. Align the bolt holes for a key position.

Most major brands offer blocked crossover passages. I have not had any problem with either embossed or paper gaskets. It is recommended, not only by myself, but others here, don't use the end seals and use a 1/4 inch bead of RTV to seal. Place the manifold in place, let cure overnight, then trim the bead if desired. BraKleen®, lacquer thinner, or alcohol will clean the surfaces for the RTV to seal.

The stock type rockers will work with that mild lil' ol' cam you chose.
Above that you would want factory or aftermarket long-slot rockers.
I would not recommend the stock pushrods if you buzz the engine at the track frequently. Occasional street use you should be fine.
The cam will make power to 6300rpm or there about in a 396.

Thanks everybody for the replies. Should I use the long slot rockerss or just go with stock? Has anybody used the PRW spotsman tip rollers? They list for $109 a set. What pushrods should I use?

The cam specs are:
Duration: 224 int./230 exh. Lift: 0.515 int./0.520 exh.

Clint

A friend of mine raced pro stock in the 1970 thru 76 time period. He had nothing but stamped stock rockers on any of his engines that he used from 1970 thru 74 before he switched to a roller cam. He was using many different cams,and started out with the stock ZL1-cam(.620 lift) and progessed to many of it's GM and General Kinetics variants. he shifted all of them at over 8000 rpm. He claimed that one up side was that the stock rockers were forgiving in the area of pushrod length. The large sled type contact pattern always hit the valve evenly even if the pushrod length was way off. Back then they ran 7/16" stock pushrods,but today you can do better with even budget 3/8" pushrods. My experiance is that you would gain very little or nothing with roller rockers in both terms of durabilty or performance.
:yes:
Not until your motor is requested to rev very high (Now that's a new term for 'punching it') do you need the stability of roller rockers with a shaft system. But stability isn't the whole story. Rollers force you to make sure your valve geometry is correct. They also reduce valve guide wear. But whether the rollers or the guides die first is a crap shoot.