Vortec If you look at the under side of the pistons you will usual see the extra weight in the design in the wrist pin and skirt area.
the top thickness is limited by the wrist pit location relative to the under side of the piston deck. with a long rod length, the pin is higher,
or closer to the bottom of the piston deck. You could have custom pistons made to maximumize this thickness,but the manufacturers will get in your wallet.

Larry Hofer

Yep. I should have said 7/16-20 thread.

Any news here with Dart heads on N/A motors?

PM Crayola Crazy. He has used the stock ported heads and the DART heads. He can tell you what does and does not make power.

Ive used the stock ported heads and have Raylar heads now. From what I've read, the DART heads dont flow like the Raylar. Yes, you can port them but then you are over the cost of aluminum...

Are you referring to a built motor or as a replacement for stock? Curious what bolting on a set of Darts is good for horsepower wise.

I went from stock to ported cast iron heads and a Raylar cam. maybe 30-40 HP increase (maybe) Then, blew them up and built Raylar 600's with aluminum heads.

Crayola is supercharged and I think he might be around 830 HP with cast heads

The darts have to be significantly better than stock ported, don't you think?

Wonder if the raylar cam really improves anything over the HO cam?? Referring to the low lift cam to use with stock pistons.

LOL - I know where you are going with all this now.

DONT DO IT.

Yeah, You can do DART heads and a bigger cam but the added HP and RPM will wreak havoc on the stock pistons. Porting the heads with the smaller cam isnt worth it. Since you will be working on it put forged pistons in it. I think diamond or somebody (summit has them too I think) has them for $650. Spend a few more and you can get the roller rockers too - worth it as well. Check around. There was somebody who just did a budget build and got most of the stuff from Summit. THEN you can do the big cam and it will be worth the upgrade and willt be worth it. Dont foget to re-flash your ECU.

The issue with just slamming some pistons in is that the assembly should be rebalanced. Then it is a bunch more work and money. I think then the value proposition goes away and just makes sense to change the motors to 525s or similar.

Good morning to all those with extra time on their hands. Just a couple thoughts. First ,the Dart heads.; good part. The biggest draw back in my opinion is that after you buy the heads, you now also have to buy all new valves and spring components. None of the stock 8.1 iron head parts fit. This adds cost and effort and not every body has sources for valves and springs. And they still weigh 76 LBS! They still make good power but you have to put them all together. The stock iron heads can be ported and cleaned up, but will never be able to match the air flow of the dart or Raylar heads because of the thin wall casting and short side Radius. Also the Raylar heads weigh 38 LBS so no smashed fingers, better heat transfer and higher compression which adds HP. Also mine come complete.

Pistons,,,, Another subject... stay with forged. You can put the Silvalite cast pistons in but then you are replacing a weak piston with a new weak piston. Have heard of forged pistons to replace the stock cast pistons, but I've never seen any. So that generally leaves replacing the cast pistons with custom made forged pistons and H beam rods that use the .990 wrist pins instead of the metric wrist pins. That is what I use. No more trouble with durability. It would need to be balanced, however they are generally lighter than stock cast pistons and rods. This is also a normal machine shop build step. This can all be done for much cheaper than buying a Marc blue 525 engine. And 525/ 600 Hp out of a 496/8.1 is easy.

Rockers,,, you can buy anybody's BB 1.7 rockers, buy ARP studs and install them on your heads. Fits well, then try to fit the valve covers. Woops wont fit. Then you can make or find spacers to raise the valve covers. What a pain. Will they leak? Next choice is to cut down all the polley locks and the studs to fit under the valve covers. What are those dimensions? Trial and error. Got a lathe in your shop? How much time does that take? With race engines, I would spend the time to do all that just to put a stud girdle on it for stability, or Crower makes Shaft Rockers for the 496. Wonderful parts. Looks like jewelry. But for 95% of the 496 engines you can just buy my Stainless Roller rockers and kit and be done in 45 min. A little more money but works every time. When you add up the cost of all the ARP and rockers and the time you need to spend , sounds like a good part.

Some people just enjoy the art of building parts. So do I.

Larry Hofer