Forged or Cast Pistons?

Hey guys... what would anyone here recommend - er wait, before recommendation, whats the difference between forged and cast pistions? Should I also take weight into consideration? (Whats the stock weight of a 305 piston?) I want something thats going to last me a LONG time. What do you guys think would be better for me... I'm most likely keeping the engine a standard 305, just with a little kick unless it needs to be bored in which case I will only bore to .30 over. I'll be running roughly a .3" lift cam, with a performer Edelbrock carb and intake. I want it to be long lasting, but a little "ballsy" so to speak. Any advice or info would be great. Thanks guys!

Oh, I almost forget, the car's an '84 Chevy Caprice Classic sedan, w/ the 305 - 4BBL, and TH 700-R4 tranny. NO emissions or ECM though.

sounds like a torquer lol with that cam, i bet it will max out before 5000 rpm. as for the difference between cast and forged, it's all in the process they are made. Both are aluminum, and the difference is that cast pistons are usually the stock version and they are better for longevity because of the fact that they do not expand as much as the engine warms up from a cold start and can therefore be run with tighter clearances, with less chance of piston slap that is very detrimental to the life of the engine. forged pistons are high performance and are very strong compared to cast, but they expand much more when warming up and have to be used with wider clearances due to this fact. There is a piston in between as well, called hypereuctetic, which is also very strong though weaker than forged, and also does not expand as much as forged, making it have the best properties of cast and forged put into one thing. hypereuctetics are what i have in my 383.

however for your power desires and your wanting for longevity, cast pistons are perfect for your application. they can easily take up to, and even over, 400 horsepower, which even a 350 can't hit without a larger-than-stock cam and some good cylinder heads, let alone a 305.

as for the weight, i have no idea. You might try going onto jegs and searching for cast 305 pistons, which would be 3.75 inch bore i think, before accounting for any overbore, which you said you might get done.

Personally I would go with hypereutectic pistons, such as Silvolite/Kieth Black, due to the fact that a) they're stronger than cast, b) they're cheaper than forged, and c) there's less cylinder to skirt clearance, reducing side loading and skirt wear due to piston slap.

Unfortunately I can't seem to find flat topped cast pistons for a 305, but hypereutectic seem to be in abundance. What about these guys? I found them on Summit Racing. Jegs didn't have much of anything for a 305. H534CP/020 Federal Mogul hypereutectic pistons in 3.756" bore.
Click on the picture to bring you to the Summit website.
http://static.summitracing.com/global/images/prod/norm/stl-h534cp_w_m.jpg (http://store.summitracing.com/partdetail.asp?part=STL%2DH534CP&view=1&N=700+150)

Federal Mogul is a very good, OEM-quality brand. Very solid. They are the makers of Michigan 77 bearings, Sealed Power rings/lifters, Carter carbs, etc.

How could I have forgotten about Fel-Pro or Champion Spark Plugs? Also F-M.

One more question... this time its about the rocker arms. Does my car have the 3/8" or 7/16" studs, and do I have the 1.5 or 1.6 ratio from the cam to the valve? Oh, and since they're not self aligning, how do I keep them lined up and where they should be?

3/8 and 1.5 are stock. Don't use the 1.6s until you've verified there will be no piston-valve interference. Self-aligning rockers are only necessary with the 1987-up centerbolt heads as these don't have guides for the pushrods. Yours will have the guides, so the self-aligning rockers are unnecessary.

Unfortunately I can't seem to find flat topped cast pistons for a 305, but hypereutectic seem to be in abundance.

Hypereutectic alloy pistons ARE cast. They are simply cast of a different aluminum alloy (higher silicon) than that used for conventional cast pistons. They're a good bet for anything that won't see any boost or large injections of Viagra gas (N²O). They are really inexpensive, so that's probably why you're having difficulty finding "conventional" alloy cast pistons - Nobody wants them any more, and the price is the same.

So, how would these rocker arms work for what I'm trying to get.... a basically daily driver thats gonna pack a small punch, but will still be long lasting. I know aluminum rockers don't last quite as long, so these steel ones should be good. I'm just worried about them cracking or breaking from the miles of temperature changes and in consistant pressure.
Again, click the picture to bring you to the product overview.
http://static.summitracing.com/global/images/prod/norm/cca-1301-1_w_m.jpg (http://store.summitracing.com/partdetail.asp?part=CCA%2D1301%2D16&N=700+4294908216+4294840138+4294889107+4294925024+ 4294925232+4294924497+4294839887+4294878249+429490 0391+4294878220+4294804217+4294863060+115&autoview=sku)

I'd say those are perhaps a little overkill ... the regular Magnum roller tip cast chromemoly rockers are probably a better bet overall. Hey, I have a set that has over a quarter million miles on them and are still on the clock strong.



http://static.summitracing.com/global/images/prod/large/cca-1412-16.jpg (http://store.summitracing.com/partdetail.asp?part=CCA%2D1412%2D16&N=700+400114+4294908216+4294840140+4294889107+4294 839887+4294804217+4294863060+4294863040+4294925024 +4294900391+115&autoview=sku) Click it!

Comp 1317s are premium rockers, but come with a premium price. I'm running the 1317 and 1318 (mixed on int/exh on my '94 "Beater" and am very pleased.

Was there a performance difference from before and after you installed the rockers?

I used these rockers during my rebuild. I don't know how the engine ran beforehand as I got it with a spun #3 rod bearing with 60k miles on it (oil pump pickup tube fell off into the pan).

I have used them on a 305, and as a before-and-after situation. I didn't really notice a large difference, but economy seemed to go up a little. I did notice a little difference at speed, with the rockers it seemed to have a little more 'hang time' than before - top end was increased by about 2-4 MPH.

Sounds resonable enough to me. I'm ordering them! I wasn't expecting instant slow lumbering 305 to an 800 HP powermonster from a set of rockers (although that'd be SAHWEET). But as long as theres a noticable difference (especially in fuel economy) then I see it to be worth it. They advertise that it gives your valvetrain a longer life too because it puts less strain on the valve guides too.

Sounds resonable enough to me. I'm ordering them! I wasn't expecting instant slow lumbering 305 to an 800 HP powermonster from a set of rockers (although that'd be SAHWEET). But as long as theres a noticable difference (especially in fuel economy) then I see it to be worth it. They advertise that it gives your valvetrain a longer life too because it puts less strain on the valve guides too.

That's actually the reason why I got them. The valves I bought were $10/each so there's $160 - plus I went with thick-walled silicon bronze valveguides for long life and I didn't want to side-load the valves into them, as can happen with standard rocker arms.

Silicon with those rockers you posted, do you need the taller style valve covers, or will the stock ones clear?

Silicon with those rockers you posted, do you need the taller style valve covers, or will the stock ones clear?

Stock size is fine, I've run stock covers on it the whole time. They're about the same size as OEM stamped rockers.

Stock size is fine, I've run stock covers on it the whole time. They're about the same size as OEM stamped rockers.

will the ones Petea216 posted clear stock covers to, or no?