I was thinking about not doing an LSx swap but I may have a trade worked out so that I would end up with an LS1 block with 22K miles on it. 01+ LS1s are identical to LS6 with respect to the block and intake (heads and cam are different). But anyway it would have a Corvette "bat wing" style pan. I am guaging what else I would have to buy to make the swap happen??? Obviously I would need a tranny...I want a 4L60E (Auto) as I don't want to put pedals in my Firebird or adjust the center console too much. I'm assuming the F Body pan will bolt right into place of the Y Body (Vette) oil pan?? Will stock C5 exhaust headers work with an LS1 swap into an thirdgen? I know that I will need an ECM and harness (for Auto tranny). What else am I missing...will probably buy the LSx swap K member from Hawks? What about fuel...will the stock LSx fuel rail attach the 91 TPI style fuel system? Trying to see what the overall cost would be...if I get a stock LSx long on trade..it will open up my wallet for other parts.

Correct. Along with the pump pick-up and windage tray.

No. Since you say below you are looking at Hawks for a crossmember, see their site for long tube headers. Or, get stock 4th gen exhaust manifolds and have a y-pipe fabricated.

More commonly referred to as a "PCM" - powertrain control module.

If you can afford it, it avoids a few other hassles.

No. The LSx system is return-less at the engine. You'll need to regulate the pressure one way or another - the swap sticky discusses it.

Really depends upon what all you get with the engine. The more the better, typically. "Longblock" usually means a bare engine.

Is there a big difference between the C5 stock manifolds and the Gen 4 Fbody...seems like I could just do a Y pipe to the C5 manifolds..unless there is a physical difference from the Gen 4 vs. the C5 that prevents the use (maybe this is what you are saying?).

Right and since I would be getting the long block free (well for trade on something I already purchased) I can afford to dump some $$ on a good K member without having to cut my stock k member for the ac unit.

Actually the 97-98' was returnless at the rail on the engine, starting in 99 the return ended up being on the filter and not the rail. I converted my 01 TT Z to an AFPR and tapped the middle of my fuel rail for the return..it supported 1k bhp with 60 lb injecter, LPE Fuel Pump, and KB BAP.

So since I don't have a rail I could either buy a 97-98' or a new style rail..I see some guys swapping in the plastic 4th gen fuel tanks with lines...is it really necessary or can I just add a return line and hook up to the existing 3rd Gen fuel tank and lines? What works the best?

C5 manifolds won't fit, the geometry is physically incompatible.

You're going to spend major $$ and/or time scrounging up all the bolts and miscellaneous fasteners, accessory brackets, throttle body, etc. Way more cost-effective to get a complete engine than to start with a longblock and buy the other parts.

Your questions about the fuel rail and whatnot are covered in the FAQ.

I went with a long block 5.3, I wish I would've bought an LS1/T56 combo instead of trying to peice this thing together. It's seems like I'm spending more time and money finding all the part numbers for all the accessory drive bolts, brackets, etc. My opinion would be to save your money and buy an engine/trans combo from an F-body. Just my

I understand what you guys are trying to say but let me paint the picture a little differently.

I would be getting a take out 01 LS1 long block out of a Vette (no outta pocket expense) with all of the accessories on it...just no, tranny, pan, PCM harness, or alternator (which I have). The question is will the way the serpentine accessories from a Vette fit the same way as an Fbody LS..obviously I would have to get a mechanical TB...I notice the alternator is high on a Vette and from what I can see many of you have them low on the drivers side???


I found a rebuilt 4L60E for $600.

It looks like I can use the stock third gen fuel system if I install a return...does it seem worth it now??

OK, in purely financial terms it sounds like you wouldn't be out a whole lot, so that's cool. You'll still need an intake manifold & probably a bunch of other minor crap,but the total cost could still be reasonable. The Y-body accessories could fit, but the PS pump is going to be close to the steering box, so you might need to work around that... Otherwise I can't think of any reason that that accessory drive wouldn't work for ya.

Good luck, post pics so that we'll all know!

Cool I have the intake as well I forgot to mention. But I have not committed to this yet as I want to understand more of what is involved. I simply have the chance to do a straight trade for a take out low mileage 01 LS1..it has an LPE cam already in it (GT2-3) I think (not to big) and it is on a 117lsa.

I guess worse case if the pwr steering pump is too close with the Y body accessories would be to get the F Body. Here is what I anticipate having to buy with your guys help.

4L680E Tranny $600-800
Headers or Gen IV Manifolds $699 (on sale now with Hawks)
TB (Mechanical) $150
PCM & Harness ($150) sent into Hawks for conversion ($800)

Spohn K member engine and tranny mounts ($700)

fuel component parts $200 (to be used with stock Fbird tank and lines)

So I'm in it for about $3300...additional to the LS1 long block.

Did I miss anything?

Thanks

You missed quite a bit. Fuel rail, injectors, fuel rail bolts, TB bolts...MAF sensor, oil pressure sensor, CTS, IAT, O2 sensors...transmission bellhousing bolts. Probably more that aren't coming to mind.

And you'll want an exhaust system, right?

OK I forgot to mention that I had the fuel rail and injectors...and all sensors..in my post above I mentioned it was a long block take out motor from a Vette..so it has a lot on it.

When I purchase the 4L60E tranny it should come with the bell housing and the bolts.

A question regarding the tranny, will it bolt right up to the driveline of a thirdgen?

The nice thing about late model 01 LS1 is that they are the same block and intake as an LS6. I have some LS6 heads but I may go directly to some ETP or AFR heads for this setup...since the motor is already out. I know a guy that made 470/400 with a healthy cam, ETP heads, LG headers, Vararam, and pully.

Maybe it would be better if you listed what all it comes with. Starter and bolts? Flexplate and bolts?

Usual terminology for "long block" is just the engine itself including the heads and valvetrain, so take a hard look at what's there and what's missing.

Price out an F-body oil pan, new pan gasket, possibly the oil pickup tube as well.

It depends on what driveshaft is in the thirdgen. V6 shaft, no. V8 shaft, yes in all cases I've seen.

Intake, yes. The block you'll want to verify via the casting number if that's important to you.

Well I know that I am definetly going to need a new pan, and I'm assuming that uses a different pickup tube considering the Y body is flat.

The current drivetrain in the 91 Firebird is a TPI 5.7 liter with 700R4 w/50K original miles on it.

That's good to know that the stock driveline will slide right into the splines on the back of the 4L60E tranny.

I will be doing a lot of reading on this site for a while and will be posting questions. I have removed, rebuilt, and replaced the LS6 in my TT Z06 a few times, as well as removed, rebuilt, and replaced the L98 in my old 87 IROC I had years ago...I have a shop, lift, and all of the tools. What I am trying to gain here is the experience from those that paved the way already so that I don't have any wasted or inefficient use of time and or $$.

I find it odd that Hawks will do a harness assembly for $900..but you still have to supply them the harness. Seems like for that much they would supply the harness.

The other thing I am trying to confirm is whether the accessories setup from a Y body will drop into a Thirdgen as will the accessories configuration of the F bodies.

I appreciate everybody's assistance. I have helped a lot of people on the CF with respect to their C5's and FI...so I realize how important it is on both ends when needing and giving advice.


Kevin (my name too).

When you're done locating and buying a harness, their approach might not seem as odd.

And if you spend time mapping out all the modifications needed to make the factory harness useful, their price point will seem like a bargain.

If you find otherwise, start a business and compete with them.

Actually I don't want anything to do with the automotive business and the reason I am getting the LS1 and parts is because I traded it for a hood mold that I owned. Can be seen on my TT Z.

I have read some guys on here reading the pin outs and making the mods themselves. Did you buy a Hawk's harness for your swap? Was it just like hooking up a factory harness? Did you take out your original PCM and put the LS1 PCM in it's place or did you simply locate the new PCM do a different location and unplug your old one?

I mapped out the LS1 engine harness, and my chassis C100 and C207 connector pinouts. Then just mapped pin to pin as needed, plus all the 12VDC feeds.


I bought an '00 or whatever truck chassis harness from the junkyard, as well as the C100/C207 connector hoods. Harvested the wires and connectors I needed from the '00 truck harness so everything is the factory color and gauge. No cutting on the LS1 harness, and no cutting on the 3rd gen chassis harness.

When that harness was built, it was plug 'n play. All four connectors on the LS1 engine harness side plugged in, the 3rd gen C100 and C207 plugged in, the three relays (fan 1, fan 2, fuel pump) plugged in.

Here's a shot of the built harness during construction:



The rest was fused 12VDC feeds from the battery, using an LT1 car 2-pole hooded block I got from the junkyard. Other guys have used under-hood fuse panels and that is a much better approach.

I modeled the harness routing with rope to get the lengths accurate before cutting and soldering on the Metri-Pak connector pins.


I ditched the factory ECM. The LS1 PCM runs the show.

Nicely done and very impressive. I can see the validity of your previous comment that it might be worth it given (or the cost of Hawk's harness not so odd) the amount of time and effort needed to make the harness PnP.
I want to make sure my air bag is still functional...so it will be interesting to see how that plays out.

When I'm finished I want it to look as factory as possible and not just like some LS1 stuffed into a thirdgen and simply rigged so that the motor will run but have none of the other functionalities...if that makes sense.

Thanks! Back in 2004 when I did the swap, there weren't many options for sending the engine harness in for rework.