392 pistons in a 354 ?

MRHP · Post by **MRHP** » Mon Dec 01, 2003 11:53 pm

Hi all. I am a new guy here and have a few questions. I am working on a 354 truck motor and am wondering what has to be done to use 392 pistons with this set up. I also have read I should get some car heads instead of my truck ones. Any help would be appreciated. thank you!

panic · Post by **panic** » Tue Dec 02, 2003 8:51 am

IndustrialHemiGuy · Post by **IndustrialHemiGuy** » Wed Dec 10, 2003 9:53 pm

mrhp,10.5, 392 pistons make 9.5 compression ratio in a 354 (this is information from piston mfg, I think it was Keith Black). For the street, (unblown aplications) this should be a very good ratio. Your block would have to be bored approximately .062" to get to 392 std size of 4" I would not bore the block any more than absolutley necessary to run these. P.A.W. has the 392 cast pistons in std 4" bore size for a fair price. GOOD LUCK , DEAN

MRHP · Post by **MRHP** » Mon Dec 15, 2003 8:02 pm

thanks for the info. Any other secrets on these motors you care to share? If you do, please e mail me. I have built many motors but never a hemi. Do you use the 354 rod with this combo? thank you very much! Brian

IndustrialHemiGuy · Post by **IndustrialHemiGuy** » Mon Dec 15, 2003 11:24 pm

Yes, use the rods that came with your motor. Wrist pin size is the same in all chrysler 331-54-92s @.991" these motors develop a bunch of torque, I had a pickup with a 354/435-4spd and 2.76 rearend gears. I switched the rearend gears down to 3.23 and I think the truck was quicker accelerating with the 2.76 ratio. In short, set up your vehicle as if you were running a big block motor. DEAN

MRHP · Post by **MRHP** » Tue Dec 16, 2003 12:54 pm

THANKS FOR THE INFO. I REALLY APPRECIATE IT!

TrWaters · Post by **TrWaters** » Tue Dec 16, 2003 9:52 pm

http://home.together.net/~twaters/

392heminut · Post by **392heminut** » Tue Dec 30, 2003 7:06 pm

panic wrote:Compression distance about .080" too tall.

Wrong! Stock 392 pistons will work fine in a 354 block bored for them. I've built one 354 with stock 392 pistons, and getting ready to build another.

panic · Post by **panic** » Tue Dec 30, 2003 11:11 pm

dodgedifferent2 · Post by **dodgedifferent2** » Wed Dec 31, 2003 2:05 pm

check the bore size.....most shops recomend not going over 0.06 with oversize pistons...it can be done but its a risky position to screw up your block!

Bailiesdad · Post by **Bailiesdad** » Wed Dec 31, 2003 6:21 pm

I have done it to 4-5 low budget rebuilds, works fine for low power engine.

MRHP · Post by **MRHP** » Thu Jan 01, 2004 7:54 pm

I am waiting to hear from the machine shop about the bore on my 354. I will also be using the pontiac 400 connecting rod on my build up. Does anyone have any specs on how much narrower the pontiac rod is from the 354? Will the extra clearance pose any problems. Thank you for all the help!

panic · Post by **panic** » Fri Jan 02, 2004 11:29 am

MRHP · Post by **MRHP** » Sat Jan 03, 2004 8:40 pm

thanks for the info. I like to do some research before I build a motor. You gentelmen are quite helpful thank you!

392heminut · Post by **392heminut** » Mon Jan 05, 2004 5:00 pm

panic wrote:"Wrong"?
The compression distance is the same? What does "wrong" mean?
I didn't say they don't fit, I said the compression distance is taller.

No, you said ".080 to tall". To most people "to tall" means won't work!

panic · Post by **panic** » Mon Jan 05, 2004 5:23 pm

TheHEMI.com

392 pistons in a 354 ?

392 pistons in a 354 ?

392 4 inch pistons in 354