What Can I Swap In To Replace My L31?

Dyabolical · March 11, 2009

So i have a 97 z71 extended cab, original stock 350 with ~235k on the odometer. I am wanting to find an engine and rebuild it. I would rebuild the engine that is in the truck but i can't have the truck parked for that long because it is my daily driver and i don't have anything else available currently.

So, what engines can i use that are typically easy to find and cheap?

L29er · March 11, 2009

I would recommend a GM HT383E, gm is probly givving them away, but I`m sure you could find a 350 for cheap, make sure its a newer block (like the one in your truck) that will have a 4 bolt main, one-peice rear seal and roller lifters and vortec heads. then re-build away, again if you can afford it throw a 400 sb crank in it some big rods and conservative ratio pistons and you have an awsome engine for your rig!

NFSGamerUSA · March 11, 2009

I would recommend a GM HT383, gm is probly givving them away, but I`m sure you could find a 350 for cheap, make sure its a newer block (like the one in your truck) that will have a 4 bolt main, one-peice rear seal and roller lifters and vortec heads. then re-build away, again if you can afford it throw a 400 sb crank in it some big rods and conservative ratio pistons and you have an awsome engine for your rig!

+1 on the HT383E if you're looking for an easy bolt-in replacement. The only thing you'll need to have done is get the PCM retuned by Black Bear Performance, but it'll still run (although I'm not sure how well) without it.

Is there something wrong with the engine, or are you just wanting an upgrade? The L31 will last a very long time if you maintain it. My great uncle has a 1998 K1500 Sierra Z71 with it and it has nearly twice the mileage of mine, close to 300k miles.

Zembonez · March 11, 2009

You should be able to find a same year (or newer) 350 pretty cheap and then do a performance build. It's easy to massage an extra 75-100HP out of one and still be plenty and daily driver reliable.

http://www.jegs.com and http://www.summitracing.com (my favorite) will be your new friends!

pennzoil29 · March 11, 2009

You should be able to find a same year (or newer) 350 pretty cheap and then do a performance build. It's easy to massage an extra 75-100HP out of one and still be plenty and daily driver reliable.

http://www.jegs.com and http://www.summitracing.com (my favorite) will be your new friends!

You can also get a brand new L31 for less than $2500.

http://www.crateenginedepot.com/

Dyabolical · March 11, 2009

The HT383s are around 5k from what i have found. I am trying to keep the whole project under 1k. The engine has oil leaks, super low compression, and a list of other problems that i just want to get rid of.

Mike G · March 11, 2009

.... I am trying to keep the whole project under 1k.

Ouch! You could probably find a salvage yard motor ($75-$150), strip it down and have it clened and freshened. Rebuild with all the parts (new rings/bearings/gaskets of course) but a hotter cam and new lifters. The heads can be gone through and you should be set. I just had my 92 done, old motor gone through and hopped up a bit, cost was $2500 out the door in less than a week. If you have the time and space to do it yourself, you can of course save the labor. Considering everything else I have, it was worth the cost and I ended up with something better than a crate (can't really appreciate the engine) motor.

--Mike

uh6tdrvr · May 9, 2009

Pretty hard to stay under a grand, more realisticly you will be closer to 2 unless you can do it all yourself. IF you can you are still going to be close to 1k just in rebuild parts. Make sure before you buy anything you have the block and the heads checked for cracks, youd hate to put all your money into a build to realize at the end there was a cracked or warped head. just my 2 cents.

txab · May 9, 2009

You should be able to find a same year (or newer) 350 pretty cheap and then do a performance build. It's easy to massage an extra 75-100HP out of one and still be plenty and daily driver reliable.

http://www.jegs.com and http://www.summitracing.com (my favorite) will be your new friends!

+1