[Tommo99]

Hi Gents, looking for some advice preferably from someone who has done the same or similar install, im building a resto mod out of a 1970 Formula 400, i have purchased a 6.0 all alloy LS with a 4L80 transmission, its done 15,000 miles. I have an install kit which includes engine and transmission mounts, sump, headers, electrically im sorted with a stand alone harness, can anyone tell me will i need to cut the tunnel up for the trans to fit? what have you done driveshaft wise ? im running the stock 10 bolt diff right now, im guessing the pinion angle will be wrong and need sorting out? I have a fuel system kit that includes all the pumps, surge tank hoses clips etc etc..........if there are any other majors that ive not thought about can you let me know cheers

[72projectbird]

4L80E will fit in the stock tunnel. I usually just have a new driveshaft made, but you can have your original cut down and reworked. I've never had an issue with pinion angle. The new trans isn't a whole lot longer than a TH400, so nothing really gets out of whack.

[Tommo99]

Thankyou, the new driveshaft you had made was it 1 piece or 2 piece with a hanger bearing? can you remember which engine mounts you used? and watching videos i see guys talking about a steam line back to the radiator? Is this something i will have to do cheers

[72projectbird]

Originally Posted by Tommo99

Thankyou, the new driveshaft you had made was it 1 piece or 2 piece with a hanger bearing? can you remember which engine mounts you used? and watching videos i see guys talking about a steam line back to the radiator? Is this something i will have to do cheers

Just a regular 1 piece driveshaft. I use ICT Billet adapters on the engine that allows you to mount traditional SBC engine side mounts to the block, and regular frame side mounts off a 73-81 Camaro (the early 2nd gens had different style frame mounts).

The steam line can be plumbed a few ways. I currently have mine going into a spacer mounted between the water pump and the block as I needed to space my water pump out to match the accessory drive. You can also drill and tap a small barbed fitting on the top of the water pump and run the lime that way. You can also install an adapter in the upper radiator hose to run the line there.

Something like this:

https://www.ictbillet.com/products/1...DEwB2NSjySjorR

[Tommo99]

OK thankyou appreciate the help cheers

[72projectbird]

Originally Posted by Tommo99

OK thankyou appreciate the help cheers

No problem! Any other questions just ask. I've built a few of these cars with swaps, so I've gathered a bunch of info along the way.

Keep us updated!

[Scarebird]

Grounds, grounds, grounds.

Make sure you harness, block, etc. are very well grounded.

[Tommo99]

Thankyou, im new to this LS game, i have a 66 lemans with a 400 and 5 speed tremec set up and i also have a tri power 59 Catalina that i built a few years ago, we dont have a lot of speed shops here in New Zealand so very hard to get pontiac parts, so i have to import everything which costs a lot, over the years i have used mainly Ames, OPGI and second hand dealers like Franks Pontiac parts, with this Firebird ive bought parts from Franks, Year one, Firebird Central, classic industries so far so appreciate any help i can get with where to source LS stuff. Will try and post some pictures of this car soon, it was in pretty bad shape body wise but we have got the body back to the blocking down stage just got the nose cone and park light valence, Hood to fit and gap up then im not too far from the paint shop.

[Cerberus]

I have a 73 formula - original manual without air that had a 5.3 LS and Tremec TKX 5 speed installed. It was built prior to my ownership. There were no modifications needed to the trans tunnel, the TKX fits nicely. There are modifications to the hood due to the alternator is situated too high (serpentine set up), and the air cleaner (ie. - carbureted, not fuel injected). Let me know if you need any pics.

[Gator67]

I just finished an LS swap (stroked LQ4) in a '79 TA (TKX & 9"). A local shop here built a new driveshaft. The car is lowered and to get driveline angles right I shimmed the transmission a little and played with pinion angle (running a 4 link so this was easy). I ran the streamline into the port in the LS swap radiator from Cold Case. Other majors? I'm running Spal brushless/pwm fans in a thick shroud, which keep the temps under control even here in AZ in the middle of the summer with the AC blasting. I'm also running a Vaporworx ReturnX fuel controller...it adjusts pump speed based on demand using an external map sensor. This way the pump isn't running full blast all the time...it reduces heat and flow back through the return when demand is low. Not sure what headers you have but if the car is lowered you can run into ground clearance issues. Ended up with a set of long tubes from Ultimate Headers, they tuck up nicely. Finally, running a Mighty Mouse catch can PCV set-up and a Wegner accessory drive.

[Tommo99]

Thanks guys for the free advice, ive made a blue with the information i gave at the start of this thread, the trans is actually a 6L80 not a 4L80, still basically the same size? my buddy at work has built a few LS engines and done the computer mapping etc, im just about to order a AFM/DOD delete kit and camshaft from BTR .

[Scarebird]

Originally Posted by Tommo99

...the trans is actually a 6L80 not a 4L80, still basically the same size?...

Unfortunately not.

The 6L80E hangs down a lot lower than the 4L80E, which is essentially a TH400 with overdrive but run by computer. A friend has a 6 in his 68 SS Chevelle; it hangs down too low for me to accept.