Anyone recommend any? Preferably with a big dish for boost.
I don't want to pay to have the block bored .030 over. Can I rebuild the engine and just replace the pistons? Will I need to get it balanced?

Reason for the new pistons is boost but not too much ~10# maybe more but haven't researched so I am not sure of the max boost with stock crank
(heard max hp is ~550rwhp) Heads may have combustion chambers worked to lower compression if it is adviseable?

 

My new motor still has a 4.00 bore, I went with Probe forged pistons. Mine are flat top, but they had a listing for dished too when I looked. I looked for Mahle's first, but they didn't have a listing for what I needed at that time, although I'm pretty sure they have them for 4.00 bores now.

 

I found these http://kb-silvolite.com/forged.php?a...etails&P_id=14

KB726 CHEVY 350 5.7 18.598 Step Dish

KB-Silvolite forged. Any thoughts on the pistons/company?

 

http://www.cnc-motorsports.com/produ...80&CtgID=12779
The ^above^ are keith black and below are Probe Industries forged

http://www.cnc-motorsports.com/produ...07&CtgID=12417
4.000 3.480 5.700 Flat Top -20.3cc 8.26 7.46 486 .927 5/64 5/64 3/16

speed pro forged
http://store.summitracing.com/partde...5&autoview=sku

which do you think are better? roughly the same pricewise

 

depending on the shop it dont cost that much to get a block bored, if you plan on running a 4.00 piston make sure that you bores are dead on, I was looking when I built my 383 and I couldnt find any 4.0 bore pistons for a 383 so I went 4.030 to keep from buying a custom set of pistons, you will need to rebalance the assembly when you put pistons in there.

 

Mahle power packs their coated and come with file fit rings.

 

Have your heads ported and the chambers opened up. Its a much easier way of lowering CR if you're low on cash for a shortblock rebuild. With only 6 lbs of boost and a stock cam, I made about 440 RWHP this way with a P600b S/C. Can always do a shortblock later.

For pistons get a custom set of JEs or Diamonds if you want to go that route. Its probably better to do a slight overbore to clean things up.

 

How much can the chambers be opened up? I don't want to go cu$tom. Engine is low mileage 68k-never raced or abused but would still check the bores.

 

well I found out the probe pistons are manufactured using a weaker grade of aluminum as opposed to my (so far) 2 other choices. Rules them out. I will be running 10# or more so stock pistons are out of the question.

 

I opened mine up to 58 CC, I dont think you can get to much more out of them.

 

I have heard 64-65 max. anyone done/had there chambers ported this big?

 

Well, here is a little more info on the Keith Black pistons. They are heat treated which should be good for boost/resist detonation right?? I don't think the speed pros are heat treated but I could not find much info on them like weight etc. not sure of the website -couldn't find it.


KB Pistons. These "New Generation Forgings" all have High Strength T-6 heat treated 2618 Primary aluminum alloy. They have Diamond machined skirt, head, mini-grooves, pin bore, gas accumulator, and ring groves. They also have pressure drilled pin hole oiling on all forgings, V-rib design for lightweight strength, and maximum piston cooling.

Do the speed pros even compare to these?? thoughts?

 

10 bux a hole to bore/hone. Around here anyhow.

 

I'm sorry but Probes are hardly good enough to be paper weights. I personally wouldn't use them in a lawnmower.

 

With my motor, I went with a .010 overbore. I just dont see the need or reason to go with a .030 overbore on a block that didnt need it. I also wanted to leave room for future builds or freshen ups. I got my pistons from J&E, the were custom ordered to my specs, and really werent much more than off the shelp pieces. Money well spent IMHO.



Nick