2001 GMC Savana 3500 Drivetrain Swap

[S.O.G.]

Alright, I have a 76 280z and an 01 GMC Savana 3500 with a 5.7L L31/4L80E

 

I know the 4L80E can be stuffed under the car with some hammering and such to the tunnel but the L31 I'm less educated on. I've been looking at the threads here that relate to what I'm doing to get some much needed knowledge. 

 

What I haven't found

- Info on mounting the motor in the bay

 

Goals

- 500hp (eventually) I'm guessing the torque will be around 550-650 if I make it to 500hp, if I'm wrong let me know

- move the power band up in rpm (should happen with cams and the 500hp goal)

- R230 rear end conversion (really just beefing up everything btwn the wheel and tranny, I drift so I'm not trying to deal with broken parts constantly)

 

Once I start the swap I'll change this thread into a journal for what I'm doing/how I'm doing it but until then I'd like to get opinions or tips from people who have gone this route before me.

 

[Domzs]

You can get motor mounts from JTR and as for the trans , you are on your own .

[S.O.G.]

Sweet, that works for me! Just picked up the doner van last night. 165xxx miles, runs good as far as I can tell. Has a few minor issues, but nothing a gasket kit wont fix. Tranny shifts just fine.

 

I was talking to a mechanic friend of mine and he said that the 4L80E wouldn't last in the Z because it was made to be under heavy load all the time. Since my z is sub 3000lbs he thought it would have a bad effect on the tranny.  My logic disagrees with him but I'm not exactly qualified to debate transmission issues. Anyone want to share opinions or knowledge on that? He was leaning towards getting the 60 instead.

[Domzs]

4L80E can handle more torque than your typical 4L60(E) . It all depends on your motor output and your car weight . It's bigger and heavy than other transmissions .

[RebekahsZ]

And why would putting something under a less-heavy load hurt it?  That is right up there with "some cars need more back pressure."  That only works with middle aged men:  I was strong when I was young, but sitting around watching TV has run me into the ground!   Don't let that mechanic DESIGN your car, although he may be great at fixing them.  You should be fine.  Always overbuild.

[Dans toy]

And why would putting something under a less-heavy load hurt it?  That is right up there with "some cars need more back pressure."  That only works with middle aged men:  I was strong when I was young, but sitting around watching TV has run me into the ground!   Don't let that mechanic DESIGN your car, although he may be great at fixing them.  You should be fine.  Always overbuild.

well spoken...LOL .   Ya he's a mechanic alright. You know every once in a while there's a bit of advice that just needs to get flushed down the toilet.

[rsicard]

Alright, I have a 76 280z and an 01 GMC Savana 3500 with a 5.7L L31/4L80E

 

I know the 4L80E can be stuffed under the car with some hammering and such to the tunnel but the L31 I'm less educated on. I've been looking at the threads here that relate to what I'm doing to get some much needed knowledge. 

 

What I haven't found

- Info on mounting the motor in the bay

 

Goals

- 500hp (eventually) I'm guessing the torque will be around 550-650 if I make it to 500hp, if I'm wrong let me know

- move the power band up in rpm (should happen with cams and the 500hp goal)

- R230 rear end conversion (really just beefing up everything btwn the wheel and tranny, I drift so I'm not trying to deal with broken parts constantly)

 

Once I start the swap I'll change this thread into a journal for what I'm doing/how I'm doing it but until then I'd like to get opinions or tips from people who have gone this route before me.

 

76 280z new.jpg

The Savana 3500 is a 3/4 or 1 ton Van.  The L31 is the Gen 1+ Small Block Chevrolet (SBC) Vortec Engine.  The Vortec heads are limited to .480" valve lift i.e. limited FLOW of air.  The 4L80E is found mostly behind the Big Block Chevrolet (BBC).  If you want 500+ HP, then purchase the Gen 1+ bare block from Summit Racing.  This would save a lot of grief.  Then purchase a Scat 9000 series 3.75 stroker crankshaft and 6.0 or 6.125 inch connecting rods.  Then get SRP (JE pistons) Professional pistons (Flat Top) with 1.125 (for 6" rods) or 1.0 (for 6.125" rods) compression height.  Then have the block final honed to fit the pistons (after purchase of them) and zero decked (top of piston level with block surface) or slightly .005" down from top of block.  This will ensure good mixture squish.  Don't mess around, get the good quality cylinder heads.  Those are the Air Flow Research (AFR) cylinder heads.  Order them with 72cc chambers and at least 195 or 200cc intake ports and angle plugs that are biased towards the exhaust valves.  If you want the TOP NOTCH AFR cylinder heads, purchase the $2000+ competition heads.  Then get 1.6 ratio roller rocker arms and compcams thick wall pushrods.  Then get a good lift compcam camshaft.  You can use either Hydraulic or Solid Roller Lifters.  The latter will allow HONEST valve lift numbers and will tolerate a more aggressive lift camshaft.  The AFR competition heads come with VERY good (stiff racing type) valve springs.  Then purchase a rocker arm stud girdle to stiffen the rocker arm assembly.  Then an intake manifold and carb or EFI.  Lastly an Electronic Distributor with electronically adjustable vacuum and mechanical curves.  Than you have an engine capable of 500+ HP and TQ.

[S.O.G.]

Yea, it sounded just crazy enough to plausible haha, thanks for clearing that up guys.

rsicard, that's some great info. After I get the motor swap working well with the 280 I plan to drive it for a while and get used to a higher powered setup then rebuild it when I'm ready for more. That will come in handy for later!