so i picked up a complete 5.3 from an 04 avalanche iv decided on keeping my rebuilt th400. My question is what flex plate do i need to buy to beable to do this swap? i remember reading about a TCI but i am not a 100% sure...if some one can post me a link that will be great

engines going in to a 74 stingray.

 

You can use the flex plate thats on the 5.3 along with the GM or Hughes spacer. Thats all you need.

 

where can i find this spacer? is there a certain measurement i need?

 

bump for help

 

The spacer is a standard part sold through the GM Performance Parts dealer network. It is .400" long and has a flange for the torque converter to sit in to prevent vibration. If you don't have a GMPP dealer in your area Skoggin Dickey (site sponsor) will be able to help.

I purchased mine locally for $37 and it requires six new bolts that are longer than the originals for around $28. The parts you need are GM PN 1256532 and six (6) of 1256533.

The spacer looks like this:


This is how it is installed.


There is also a torque sequence for the flexplate as well, if you need it I can post that up too.

 

And the flex plate holes to torque convter bolts will have to be elongated alittle as they are metric spaced an the TH400 tq convter is standard spaced.

 

can u post the torque sequence and how much torque i should use
thanks this is helpful...

also would that acessory drive fit under the hood of a 74 vette? if not i was thinking of getting a cowl hood so would it fit then?
thanks again

 

The torque sequence is a three step process in a star pattern. Make one pass at 15, then 37 and finally 74 ft/lbs. I have linked to a picture of the info on my site, but it is a bit large for easy reading.

For your accessory drive question... I don't know. I've never worked under the hood of a 74 vette, but I've seen them. The truck intake and accessory drive is quite tall and I was able to lose over 5 inches when I switched to an LS1 intake. The truck alternator sits at nearly the same height as the TB - but something that works in your favor is your car was originally equipped with a carburetor so you may have extra room.


One guy on here used a functional cowl hood and routed his air through it - with the car intake on his 68 vette. I thought that was a cool (no pun intended) idea but I don't have the room and can't swap hoods from the sleeper angle. He made all the piping from fiberglass and used a standard air filter. Pretty creative.


Changing to an LS1 intake creates a whole slew of other problems which can be easily or expensively resolved depending on your preferences, wallet and fabrication skills.

 

What kind of problems am i looking at when i switch to the ls1 intake? will i be able to use the same fuel rails?

 

Ahhh... such a simple question with such a complicated answer.

* The fuel rails and injectors need to match the intake. Car rails and injectors are completely different and the truck rail is super tall while the car rail is flat. Ironically truck injectors are about 40% shorter than their car brothers - flow is comparable.

* If you are using truck accessories and a cable throttle body the cruise tab will hit the upper hose outlet slightly. A die grinder will fix this but you can't have cruise.

* With truck accessories the idler pulley will interfere with the throttle body opening and needs to be relocated to the driver's side. Someone makes a bracket for this, but I can't remember who. It's an easy mod you could make yourself if you saw the bracket.

* The car pump will fix the throttle body issue (outlet is moved) but uses a different pulley offset. Some people have successfully swapped to the truck pulley. I don't want to destroy a new WP nor do I want a custom piece I can't make or swap roadside out of town. I'm not going to carry a WP "just in case." Using "car" accessories fixes this.

* Car accessories create another problem at the crank pulley... There is Y- Body (vette) offset, F-Body offset and truck offset. Vette / CTS-V is the closest to the block, F-Body is next and Trucks are the furthest away. I'm not sure where the GTO fits in this or how it compares. Vette and CTS-V accessory drives are sold new from GMPP complete for less than $800 or you can go through many vendors for pretty aftermarket options. You will still need the right crank pulley and new bolt but if the dimensions work for you that is the most cost effective and reliable setup. The CTS-V drive is PN 19155066 while the Vette is 19155067. Both require damper 12620556. These are coming with alternator, PS pump, AC Compressor, brackets, a belt, etc..

I think that covers it. If I think of anything else I'll add it.

Hope this helps eliminate confusion... I hope... I really do.

 

Buy a manifold/injectors/rail off craigslist ~$150.
Buy a Kwik performance alternator/PS mount $250
Use the truck pump and either twist, bend, OR cut the outlet to clear a cable TB.
BTW, I'm the "some people" who swapped pulleys that gofast is referring to.

 

Craig's list or eBay baby! Even check the classified section here. On the bay, there is a guy who does crate motors and has crate engine take off - never run intakes, rails, injectors, etc. for sale every day and is great to deal with. Good prices, fast shipping, quality merch, and product is exactly as described. Let me know and I can PM you his name on there.

I forgot about Kwik Performance. Their products (according to measurements) wouldn't fit for me, but they look solid. They were a first contender since S&P stuff is so high.

Gary, you and the others who mod their water pumps make me nervous. No offense, but I'm just paranoid I guess. I guess it comes from getting stranded in nowhere-ville Iowa for a fuel pump in a friends car during my high school years. Since he had a Diplomat with a common engine we only had to wait for the parts store to open, replace the pump and get back on the road!

 

Yep about craigslist. I got my whole intake/injector/rail setup for $100.
As for the water pump, I dont have a choice. No style of water pump heater inlet/outlet will clear tha A arms on a C3. So the fittings have to be removed and holes tapped. So I would carry a spare anyway.
This is in my storage compartment.

 

so i wanna use the same alt bracket and i got my ls1 manifold on it only issues are this pully blocking my TB and this pipe that comes up from the waterpump that bocks the tb also. Some one on corvette forum said theirs a kit to relocate the pulley. If i got an ls1 tb would it be able to clear the pipe?

 

I can't remember the name of the company that sells the adapter but when you see one you will be dumbfounded that you didn't think of it. It uses the three existing holes below the alternator in the bracket and simply relocates the pulley farther down and to the right just out of the TB's way. I'm not sure there is cutting of the factory bracket involved or not but it is dead nuts simple.

The throttle body only needs a very slight massage to clear the water pump outlet. Once complete you won't be able to use cruise control. I used a die grinder on mine but a Dremel would have worked fine too. It's really close but it doesn't rub anywhere in the throw.


From the front.




From the rear.


I'm not sure about the frame rail / upper A-Arm clearance compared to a 68 but if you look at the water pump Gary's68 posted... that mod was necessary for his car to clear the chassis (I always forget this each time I see that picture).

 

Just remove the pulley form its current spot. Locate the ALT bracket mount bolt just below and to the right of the idle remove it. You can get a longer bolt to place the idler there and use spacers or washers to get the track right. Or you can see if Speartech still sells the relocation bracket. Las I checked it was $100 bucks.

Then cut the tab of the bracket for were the idler was or the TB will clear!

For the water pump outlet. Heat and tweek it down. Or buy a L92 water pump as it has a 45* outlet vs the taller one on the older truck motor.

Or yoou can swap to a LS1 WP and use the 3/4'' spacers that I think speartheck sells as well.

Read this http://www.performancetrucks.net/for...S6+intake+swap !

 

so after a lot of thinking...i feel the best choice is to go with an f body set up the whole thing.
I really wanted to have my alt. on top because i remember how much of a PITA it was to change in my friends camaro.
i just dont want to deal with any clearance issues... so Garys68 is that an fbody pump or corvette?

 

I didn't think the alternator would clear even my L88 hood. So if you spent $100 for just the pulley relocation bracket, I would be afraid you would have to toss it.
The Kwik Perf bracket puts the alternator on top, and that whole relocation mount is $160. Check them out, you can use them with vette, f body, or truck spacing.
My pump was for f body, but I think the generic parts store pumps can be used with either f body or vette spacing.
I did replace the f body pulley with the truck pulley so I could keep the mechanical fan and mount the AC compressor partially in front of the passenger side head. Couldn't keep the compressor in as tight with the f body spacing.

 

you posted a relpy saying that yours waterpump didnt clear an a arm or something.

 

No waterpump heater inlet/outlets will clear the A arm upper mount. You'll have to modify something. Others have bocked the existing ports. I tapped mine and put in 90 degree adapters.