L31 engine rebuild.

**PHATSPEED7X** · 04-25-2005, 10:36 PM

I own a 1998 chevy K1500 ext. cab short box Z71 with a L31 350 Vortec motor. With 205,000mi I am thinking of rebuilding the engine. I have priced out rebuild kits with stock replacement parts, and others with high performance (mostly different cam, and value train mods). Prices are way different because if you do decide to swap for a high performance computer cam, you must change everything else. I can buy a rebuild kit in stock trim for about $450. Rebuild kit that would include everything that would work with the cam swap comes to just shy of $1200. Ouch! Has anyone ever installed a hotter cam into their L31 vortec? What kind of power gains did u get? I also have a gear drive timing set that will work with 1987 and later small blocks with factory rollor cams. Won't work in my vortec because if several issues I found out after I bought the set. Maybe I'll find another pickup to build with that accept it.

Adam Hanson
Owner of PHATSPEED MOTORSPORTS

**99ChevyZ71** · 04-26-2005, 06:49 AM

You might want to consider swapping in a 6.0. I'll probably do that when my L31 gets tired.

**97Silverado** · 04-26-2005, 06:49 AM

Originally Posted by 99ChevyZ71

You might want to consider swapping in a 6.0. I'll probably do that when my L31 gets tired.

That's gonna be a helluva lot of work and is nowhere near a direct swap!

**CKTA** · 04-26-2005, 06:50 AM

Originally Posted by 99ChevyZ71

You might want to consider swapping in a 6.0. I'll probably do that when my L31 gets tired.

Not even close to bolting up and working.

L31 crate motors are out there and pretty cheap.

**TITANIUM** · 04-26-2005, 07:06 AM

L31 means vortec heads. It is still a Gen I block.

**PHATSPEED7X** · 04-26-2005, 09:17 AM

Ya I did think of bolting in a 6.0L but I would rather save time and money with just rebuilding the L31 vortec. Besides you can't go wrong with a good old 350 small block.

**blown68ssrs** · 04-26-2005, 11:59 AM

Phat, for the budgetary purposes. Don't forget the machining cost.

**2tonegmc** · 04-26-2005, 01:37 PM

I was in the same situation about a month ago. For a good machine shop to rebuild it for me including labor and machining was going to be about $2500. But I needed new rods as well as crankshaft reworked(I spun 2 rod bearings).

If you're going to do it yourself it will obviously be cheaper. What I did was just buy a new L31 from GMpartsdepot.com, was about $2300, and comes with a 3yr/50,000 mile parts/labor warranty.