SynergyV8

iTrader: (1)

Rod failures are for car motors or truck enthusiasts who treat their heavy pigs like cars, not hauling trucks that are used for daily drivers when towing. I'd bet top dollar your stock rods are in the same perfect condition they came in from the factory. There's absolutely no reason to upgrade the rods in a motor that spends 99% of it's running life between 550-2500 rpms. If you're going to spend any money on the rods, $79.99 on ARP rod bolts seems like a much wiser choice.

http://www.texas-speed.com/SHOP/item...id=94&catid=36


If you're putting it into an S10, maybe. Not for a truck; especially an HD. Keep in mind lsx10, when recommending things for other people keep their needs and goals in mind, not yours. This motor is never going to see 6000+ rpms, and if it does, why is it in a heavy-duty tow truck?

The key here with this rebuild is to not fall into the norm of trying to squeeze every bit of power out of it as you can. 9 times out of 10 you'll end up with something unreliable or too expensive to maintain. K.I.S.S. this build, so keep it simple stupid!

old motorhead

iTrader: (10)

That sounds like a kit for a gen 1 small block chevy. 400 crank in a 350 motor with a .03 overbore gets you 383 cubies. 5.7" connecting rods are gen 1 stuff too. Will this fit in an LS motor?

old motorhead

iTrader: (10)

Unless you have iron heads, LS6 heads aren't much of an upgrade. Maybe a little less chamber volume, but if you're changing the pistons anyway, not much value there. Ports and valves are similar on your heads vs the LS6's.

zippy

I agree, that must be a Gen I/II small block.

clemsondave

Ok, so forget the 383. Keeping the stock rods and heads. Small cam with new springs (LS6 or 918s maybe?). What specific pistons would you recommend? Really hard finding anything that isn't forged. Maybe with a little higher CR, headers and cam I can gain the extra grunt I'm looking for.

Thanks for all the help guys. I know this is a little different than the usual 1/4 mile build.

SynergyV8

iTrader: (1)

$248.56 for the pistons, $98.96 for the rings. Can't go wrong here with a stock rebuild and a few valvetrain goodies.

https://shop.enginekits.com/osb/itemdetails.cfm?ID=1304

Since the stock aluminum heads could probably use a little TLC, send them to the machine shop too for a hot bath and resurfacing so you put the motor back together tighter than a tick's ***. Keep in mind, machining for 4.030" bores will raise your compression a tenth of a point just by doing that bringing you from 9.4 to about 9.5:1. I'd use the OEM replacement pistons and just mill the heads down to 66-67cc (from 72cc with the 317 heads) which will sit you right around 10:1 compression. After a new set of seals for the heads and cleaning of the valves, you'll be set for another 100k+ miles of reliability, but this time more torque and better fuel efficiency!

If it were my truck, I'd call up a cam company and have them special grind you a camshaft for your build. I'd tell the sales rep/cam grinder that I'm looking for something for a newly built 370ci motor with ~10:1 compression and it's going into a truck meant for comfortable daily driving with an emphasis on low end grunt and fuel efficiency. Finish it off with a stock-like idle but with a hint of attitude.

Edit: Oh, and for money's sake, tell the cam guy you're using springs good for .580" lift or so, but I'd keep it below that for longevity's sake. .540-.560's would be good.

1FastBrick

iTrader: (17)

SynergyV8 Posted some really sound advice about your Rebuild. No need to get new rods. Just add some better rod bolts if your concerned about reliablity and have them checked for size to make sure there is no issues.

You really should Buy the new pistons before the actuall machine work is done. This will insure there is no mistakes and that you have the correct piston to bore deminsions...

Same with the crank, have it inspected and see if needs to be turned undersized so you can get the correct bearings. Once you have all the parts and get the crank serviced, have the crank ballanced. I did this on my new 5.3 build and they actually endded up Lighten it in a few spots so that it balanced out properly to the new rottating mass. These cranks are a neutral ballance.

Same with the Heads and intake manifold... No need to run out and buy things that are not going to add any thing to the overall package your trying to put together for your work truck. Just have them rebuilt and put better springs on for a slightly larger cam. Get them milled if you want a slight bump in compression and speak with a professional about a getting a cam to meet your needs...

clemsondave

Wow! Thanks for everyone's help and your time. I definitely learned a lot. This should be a fun project! I'll let you know how it turns out.

SynergyV8

iTrader: (1)

Other benefits of having the pistons while machining the bores is that you can tailor each individual bore to a specific piston, ensuring tighter bore clearances. A tight bore is always desirable (aint that always the case ) for many things such as less blow by, less oil consumption, quieter cold starts and better running operation and more (consistent) cylinder pressure which can definitely help out in the power and fuel efficiency categories.

zippy

I would shoot for some Mahle pistons and try for a compression ratio of around 10:1-10.2:1 with your stock 317's. Have the heads gone through as they will likely need some work. Use the stock rods with Kaetech rod bolts and have everything balanced. Go for a cam something like the Trick Flow 216/220 .560/.560 114LSA for a smooth idle and more torque. I'd also have the IDC checked to make sure that you are not out of injector once it's all together. That should be all you need for a work truck.