KEITH BLACK AMC PISTONS

JERSEYJOE

Anyone know where to buy these?

1980_Cj7

I got the best price from Summit Racing. KB couldn't come close to matching their price, and flat out told me so. Go figure, a middle man can make a profit and still sell them cheaper than the manufacturer. Can't say enuff good about Summit. They have always been super to deal with.

RAMBLINFSJ

I've heard those pistons are just stock replacements if that matters to you.

1980_Cj7

RAMBLINFSJ wrote
I've heard those pistons are just stock replacements if that matters to you.

Not true. The KB 354's are something like 9.5 to 1 CR if I recall, and they offer even higher CR's. The pistons have a stepped dish that aids in quench and allows running higher CR on pump gas. Also, the wrist pins are smaller than stock AMC and need bushed.

jeepsr4ever

354's are RARE! Summit may only have one or two sets left. They were made for reducing the bearing journal on a 401 crank and destroking it for use in a 360-401 block with a chevy rod.

JERSEYJOE

OK then what are my options? I want to put together a 401 for a J-20 that will be used to tow and general service. NO offroading. I want lots of torque, dead smooth idle, regular fuel, not a lot of tricks, latest Bulltear oiling mods I was thinking about 9 or 9.5 to 1 I can use either later 401 heads of early small chamber 390 heads. One of the many RV cams on the market. I favor Engle, but am open to suggestion. Don't have any inflated HP or TORQUE expectations. I just want something that will pull like a train.

1980_Cj7

jeepsr4ever wrote
354's are RARE! Summit may only have one or two sets left. They were made for reducing the bearing journal on a 401 crank and destroking it for use in a 360-401 block with a chevy rod.

Hmm, never heard that before. I didn't have any trouble getting them about a year and a half ago, but maybe things have changed. I just checked Summit, and they are listing them. I also checked kb silvolite, and if you search by piston number, they show up, but if you search by engine, they don't. I thought they made some that gave higher compression also, but can't find them either now. We just used the stock rods and bushed the pins. Working great so far.

http://store.summitracing.com/egnsearch.asp?Ntk=KeywordSearch&DDS=1&Ntt=kb+354+pistons&searchinresults=false&N=700+115&y=7&x=26

http://kb-silvolite.com/performance.php?action=details&P_id=257[/url]

jeepsr4ever

Call them once and ask them how many they have in stock and then you will know how rare they are. If you find them in stock I can save you a few bucks.

1980_Cj7

jeepsr4ever wrote
Call them once and ask them how many they have in stock and then you will know how rare they are.

Wow, didn't realize they were that hard to come by. I thought I saw that quite a few others in here had used these pistons also. Maybe I got lucky for once in my life, ha, ha. Thinking back now, I do seem to recall Summit didn't have mine in stock and had to back order. Got them to me in pretty short order though.

I did contact KB and asked them if they could open up the pin holes to fit the AMC pins, and offered to pay extra of course. They wouldn't do it. Claimed there wasn't enough meat there to open the piston holes up. Kinda hard to believe when I saw how thin the bushings I ended up using were. I think they just didn't want to fool with them.

jeepsr4ever

Joe, Sealed power still makes forged 401 pistons. I think I can get them to you for $450 a set. You may also find them cheaper online somewhere but beware that sometimes they list a forging and it turns out to be cast!

JERSEYJOE

I KNOW THE DIFFERENCE BUT ARE FORGINGS NEEDED FOR A LOW RPM STREET MOTOR? SINCE THEY RUN A LOT MORE CLEARANCE AND CAN RATTLE BEFORE THEY ARE WARM ARE THEY NOT A PITA ON AN EVERY DAY TRUCK MOTOR?

jeepsr4ever

You should not get any rattle out of the forgings if the bore is correct.

JERSEYJOE

I always heard that since the forged run looser cold, like .005 to .007 clearance that they can rattle and scuff if not warmed up and allowed to expeand to the operating clearance of the cast ones at .002 to .003. Obviously they are stronger.

jeepsr4ever

.004-.006 for Speed pro. Most race type forgings can go as low as .003. You can be fine with cast pistons but after a little cylinder wear or about 100,000 miles worth of running the skirts fall apart from pistons slap.