Hey all, I had some questions regarding an engine swap. I am looking at throwing my SBC 406 into a 1993 Camaro Z28 with a t56 6 speed, I am pretty sure this is possible. I was wondering what all it would take to retro fit the engine into the car. Where can you buy adapter plates for older SBC's to hook up to a 6 speed. Im just needing info on the necessary mods or changes that would have to take place to make this swap possible. Im not aware of any tech articles out there. Thanks  

your 93 should have come with an lt1 which as far as i know has the same bolt pattern as a good ol small block,  although most camaros i've seen with an older small block in them have had to cut and trim the tray by the base of the windshield.  

Hopefully you don't live in California or the states that use Ca. standards with a physical inspection of the power plant as this combination is not EPA or CARB legal. If you live in a place that doesn't inspect, you'll find this is almost a bolt in.

If the 93 originally had an LT-1 or any other small block derived engine from a 4.3 V-6, to the 305 or 350 V-8s, all these will use the same bellhousing bolt pattern.

You'll need to make sure the 406 crank has a pilot bearing in it. 

The T-56 in the 93 would have a hydraulic clutch, which makes things a lot simpler.

To use the LT-1's flywheel, your 406 would require a crank that uses the one-piece rear main seal and be internally balanced. If your 406 has a two piece seal crank, as done on the old 400 engine, then you will have to purchase the flywheel that is unique to the older 2 piece seal crank. Also, if your 406 requires external balance (i.e. 400 type damper and flywheel) then your flywheel selection would also have to include that consideration. Another flywheel consideration needs to be made for the tooth count on the ring gear of 153 on older smaller diameter models and 168 teeth on newer models. Flywheel diameter and tooth count will also drive starter selection. You need to check the block for starter bolt hole locations. Many later blocks will accept mounting the starter for either, older (pre 67) blocks will not accept mounting for the 168 tooth flywheel and many newer blocks (post 95) won't accept the starter for the 153 tooth flywheel, so check this out before ordering the flywheel. Last but not least, the flywheel will also need to accept the pull type clutch of the 93 LT1.

I presume you're converting from fuel injection to a carb, in which case a drastic reduction in fuel pressure is required. There's several ways to approach this, one is to remove or disconnect the in-tank pump and install an electric pump specifically for carbureted engines. Two, is to use the high pressure pump and return plumbing. Build an orifice into the return to provide a pressure reducing continous fuel return to the tank to get pressure in the engine bay down to a steady 8 to 10 pounds, then use a carb specific regulator to drop pressure into the carb down to 5 or 6 psi. Three, go back to a mechanical pump if the 406's block has that provision.

The LT-1 fuel injection will not bolt to non LT-1 heads, there is a significant port missmatch, no coolant return capability, and way different bolt hole locations. The LT-1 injection could be adapted to a conventional intake with Moroso injector adapters welded or epoxied onto a conventional manifold.

If you can do some fabrication and light machining, the LT-1 heads can be used on a conventionally cooled SBC by drilling and tapping the existing vent holes on the ends of the head to accept 1/2 inch NPT to 5/8s hose fittings then bringing the hoses together with a fabbed coolant return housing that includes a conventional thermostat. This would also require a GMPP LT-1 to carb intake, lots of places sell 'em. 

Keep in mind that if your using V-belts, the water pump needs to rotate clockwise, a serpentine drive requires a counter clockwise rotation pump

Other than these things you're looking at pretty much a bolt in.

Bogie

luckily i live in ohio. i was planning on using the normal pumps and pulleys (power steering, alternator, and water pump) on the 406. i was not going to try and use the lt1 pumps and pulleys, also i was just going to use my holley 130 gph mecanical fuel pump. im not intending on using any of the lt1 engine parts (heads or fuel injection system) or ecu components since it is carb'd.  it is a 1972 400 block and  is a 2 piece rear main. so if i am understanding you correctly since it is a 2 piece rear main i will just have to purchase a new flywheel. if i purchase a new flywheel will the engine have to be rebalanced? it was originally balanced with an ati dampner and flywheel.  

do you kow where this flywheel is availiable. i have talked with a sales rep from JAM Performance Transmissions and he said he was going to talk to his distributor but i was wondering if they were available anywhere else

thanks

-mark

If you built the engine complete from a 72 400 and had it balanced with an ATI damper and flywheel, you should be just fine. The issue I was getting to was that an older engine with a two piece rear seal has a crankshaft flange with a larger bolt circle than post 86 engines with a one pice seal. Since your 93 engince is obviously a post 86 engine, its flywheel cannot be fastened to your 72 engine, therefore reusing it is out of the equation. The only potential issue you currently have is selecting a clutch and flywheel, that's strong enough to handle the 406's torque and the 93 pull clutch mechanism. However, I'm sure this is more an academic concern as there are plenty of pressure plate and disk choices available for the SBC to insure compatibility with the ATI at one end and the T-56 input shaft at the other.

Your 93 bellhousing should bolt to the 72 block, that will solve any depth issues related to the T-56's input shaft length. You will need the 93 style pilot bearing which should fit the 72 crank. No adapter is required given the parts you have.

Bogie

thanks for all the helpful and useful info. i believe i may have it all sorted out now. however does it have to specifically an ATI flywheel? the dampner is an ATI. i have no idea what kind the new flywheel will be. i plan on ordering the new flywheel that works with the old crank but still works with 93 pull style clutch. 

-mark

OK Mark I'm getting confused. Getting, I've been that way all day. So far as I know ATI makes dampers and bunches of automatic transmission parts but not flywheels, so how or what is the 406 balanced to? How critical is the balance of this engine? Is it going racing? Most street guys just build an engine from over the counter parts and accept the balance that manufacturing tolerance provides. If your going racing or a simply worry about balance, then all the parts that attach to the crankshaft from the damper to the clutch need to go to the balance shop. In your case that includes the flywheel the engine will run.

The flywheel, or at least a flywheel that will work, is Centerforce's 700173, it uses a 153 tooth ring gear, so plan the starter accordingly, actually I think the LT1's will work for ya. This monster is the large bolt pattern, externally balanced deal that accepts the oddities of the LT1's pull style clutch.

Bogie

sorry for the confusion. actually im getting to be that way too. it was a centerforce flywheel balanced to an ATI super dampner. it is a street engine that may occasionally see strip, rarely. so just for clarification, that flywheel will work with an internally balanced engine equipped with a dampner? thanks

-mark