The lt1 uses the same rear distributor positioning as any SBC, so you could line up the front and rear bolt holes from a standard SBC, to the front and rear intake bolt holes on a lt1 intake, and see where you need the distributor.

 

Putting the distributor hole in the intake is not the easiest thing to do. I made a specalty tool that goes into the distributor hole in the block and marks the intake where the hole needs to be bored. On top of that it's on a angle which makes it more fun.

Bret

 

ok guys, heres the real story on how this will work on a lt1 with a stock manifold. i dont see any otherway to make this work using a stock manifold so.... please read carefully!!!! i have pics on my website

http://www.cardomain.com/memberpage/534496/2

1.) the first endevor you must take on is the removal of the intake, many write ups are out there, so use the search to find out how to remove the intake...this took 15 mins

2.) you must have your motor at #1 TDC, this is a much for phasing any SBC distributor. I donno how... but i phased this like any old SBC. ... this took 2 mins

3.) remove the oil pump gear plug and set aside.. this took 10 seconds

(EXTRA STEP.. your might have a problem at the end with the distributor not lining up for #1 TDC... i learned that this will help....using a screwdriver or oil pump primer... turn the oil pump driveshaft slot to 8 o' clock from behind the motor or if your standing infront of the motor to 2 o'clock. my engine was out so i can lookdown and see the relation... you might not be able to, again i dont know if this is needed!!!!

4.) go and set your intake on a bench, using a SAZZALL or other cutting tool remove the EGR boss's on the back of the intake.. you want to make the back of the intake flat. before you do this.... look at my website pic...2nd from the top!!! you must have yours look like this... this entire process took me 1 hour.

5.) after you have cut, grinded and removed the excess material off the back of the intake... you must now weld it up... i took mind to a local welding shop... they welded the aluminum plate to the manifold for 20$ ...took the shop the afternoon to do this.

6.) now that you have the intake off and welded up... you must now get a hole in your manifold.... i didnt know how to do this so i contacted John Millican at www.LT1INTAKES.com . John took about 1 week to get my intakes back to me.... which he did all the work himself to mount the new rear distributor. the work is great but i did have a problem with fitment and help helped me out alot... good deal to me!!!!

7.) goto summit or jegs and buy a MSD low profile billet crank trigger distributor MSD# 121-84697... http://www.jegs.com//cgi-bin/ncommer...66&prmenbr=361

this is a great disrtibutor thats low and doesnt take up alota room, in my opinion this is the only one i'd use for this mod, cost me 155 from a local speed shop that price matches jegs and summit!!!

8.)i got the intakes back and installed one..... it seemed the hole was too far to the right on the manifold.... you i took a grinder and made the hole big enough for my distributor to fit, even though there is a bigger hole than needed now... it will still work. this took me 1 hour to do

9.) with the intake on the heads with only 2 bolts holding the rear down... slide the disributor down and phase it to the #1 spark plug. you can search on how to phase on your own!!!! this took 2 mins

10.) after you get everything in the right spot... re-install the intake... install the distributor andbolt everything up, go buy some SBC HEI wires (cut to fit) and install them... stock wires wont work... no LT1 wires will work as the opti has different wire plugs!!! this took me 1 hour to do!!!

11.) run a longer coil wire to the distributor from your stock coil.... i'm using a MSD 6al to make the spark hotter since it must travel farther from the coil now.

12.) start it up, light it up!!!!!

i donno about phasing or installling the distributor too much so look it up... but other than that.... this was fun and only cost me 400$.... no more opti problems!!!! you may want to remove the opti rotor so as to keep the high and low res pulses clean from debris from the rotor comming apart!!!


any questions.. pm me!!!

 

So what terminal will be used for #1 plug since your at TDC?

 

I agree unquestionably with procedure Bret suggested. That is also the method I used. That AFAIC, is the way to do it, if looking for professional machinist quality accuracy/precision. That also implies the intake is bolted up correctly to block/heads.

Edit: bolted up correctly to block/heads.....prior to spotting location of hole. No, not the ONLY precise way to locate hole, but definately, a simpler precision method.

 

So much for my post, along with caution posted by Brett.

 

I went with the Crab cap version of the Dist. Even lower and give extra room for some stuff I use. This weekend I am going to start making a setup to do this. Then i can just get them welded. bolt them on and drill them. Hole will be good to go

BTW for those who have ask the intake does NOT place the distibutor other then up and down. The hole can be as big as you want as long as it is smaller then the collar

BTW Arnie the stress on the cam is NOT increased by the dist. being in the back again. ALL the timing is STILL controled up front You just have a rotor along for the ride out of harms way now. The ONLY thing that has changed is the spark is now dipensed in the rear and not under the water pump

 

Ellis be sure to call me at work next week and fill me in on The cutting fixture, It sounded spot on when we talked
Later bro

 

I understand what is being accomplished by the procedure undertaken.
As far as stress from an out of location hole is concerned, it will be (and show up physically) on the bearing/component that will be the weakest link in the chain. The one question in doubt, is the severity. Any time there is a component rotating, and being driven axially 90* from drive plane, there is the potential of component stress, when not properly lined up.

 

I guess what I am not making clear is the block does that and the intake just needs to be cut to the angle of that hole. As long as it does not Stress it to one side or the other and is clamped down at the correct angle and hieght every thing is just fine

This is not my first adventure into this area. I learned alot in 93 about why CORRECT Distributor Hieght is needed and what exactly the hole in the intake does and does NOT do. The info was straight from Edelbrock and backed up By Holley and Wiend

What the hole does NOT do is locate the distributor head front to back or side to side The hole should also be slightly larger then the neck of the distributor yet NOT larger then the collar

Unless some thing has drasticly changed in the last 11 years on this 50 year old design that information should apply

 

Im not an engine builder by any means, but the as cut hole in the intake was much bigger than the distributor shaft, yet allowed the collar to sit on top it still.

 

If you clamp the distributor down on a surface that is not perpendicular to the distributor angle then it can cause extra loads like bending on the distributor shaft and will end up with wear problems.

It's not the easiest thing to do, that's why I always wonder on how it's done so cheap. I guess I'm just to **** to do it the cheap way.

Bret

 

This is the exact reason why I made my own fixture and took dimensions from the carb LTX intake and did it all on the bridgeport, with exact measurements.
The collar that is at an angle needs to be in the correct location, cause if its more to the left or to the right then the distributor wont sit exactly perpendicular to the hole in the block.

 

Agree 100% that the collar has to be completely perpendicular to the distributor shaft. Im still confused over how the hole loacation it self matters, as long as the collar is fully seated against the intake at the right angle. I would say there is a 1/4 inch anyway to play with and still have the collar seat.

 

How much clearance is between the distributor and firewall with this setup?