Does anyone have any measurements or dimensional drawings showing the size difference between the factory steering gearbox and the Borgeson unit. I thought there was a thread on here with that kind of information but I haven't been able to find it.

When I converted my '73 to the Borgeson system, I didn't think to measure the space around the factory gearbox for possible header fitment. I'm wanting to go with Stan's Tri-Y headers but haven't been able to determine if there is enough room with the Borgeson system. I've contacted Stan's but they don't know if their headers will fit and I don't want to risk a 20% restocking fee to find out unless I am reasonably confident they will fit.

If anyone is running Stan's Tri-Y headers with the Borgeson system, please let me know. If you are running Stan's with the factory gearbox, I would very much appreciate some measurements and photos.

Thanks,

DC

Edit: Stan's Tri-Y headers now fit with Borgeson steering. Starting reading at post #56 for more info or see this thread: https://www.corvetteforum.com/forums...-steering.html

EDIT June 14 2022: Stan has retired and sold off his inventory. He sold the fixtures for the Borgeson modified Tri-Y to his former employee, Bruce Reed, who goes by Bruce R on this forum. As of this date, Bruce is putting prices together including for a stainless steel option. He's not a sponsoring member at this time so PM him or hit his Facebook for more details. His company name is Brews Customs. Very glad to know someone is continuing to offer this Tri-Y header.

 

I think a better question to post would be if anyone is running Stan's Tri-Y headers with a Borgeson steering box.
It seems that most headers fit with the Borgeson box and any that don't just need a slight dimple put in them to get the needed clearance.
Dimples in header primary tubes, if done right, are barely visible once the header is installed and unnoticed to everyone but the person who dimpled it.
A dimple in the primary tube will not hurt performance.
I purchased a Borgeson box for my '73 and it does not seem to be much different in size than what my OEM box was.
If there is any interference between my Borgeson box when I install my new Hedman long tube headers, I'll just add a dimple and install them.
I also tried to find a definitive answer to the same question you have and nobody could provide it.
Frustrating and even more so when you have a big block and the options for long tube headers comes down to two choices.

 

Did just that back in 2018 and bumped it back to the top a few months ago. https://www.corvetteforum.com/forums...-steering.html

Only one response but no definitive information so now it's on to plan B. Hoping someone here will have some info to share that helps.

Also sent Stan's another email requesting dimensions. We'll see how it goes.

DC

 

Good Luck.

 

Well I do have both of them in the garage, and three bolts later they'll both be on the floor..... Might as well take that part out next.
I can at least get you some scaled pictures!
Give me a couple days OK?

 

No measurements but here is a pic

 

Thanks much. It looks like if there will be an issue, it will be with the #3 tube on the Stan's Tri-Y.

I did find a blurb on one of the Borgeson threads that said the gearbox was 3/8" closer to the engine than was the factory gearbox. Don't know if that's accurate. It's a little closer to the firewall as well. Not sure how the mounted height is different.

I also finally found the thread I was looking for where Jim Shea posted some dimensional drawings (see post #16): https://www.corvetteforum.com/forums...-question.html

Unfortunately, his drawings were hosted by PhotoBucket and have been watermarked and changed so that they are too blurry to read. I PM'd Jim to see if he still has original drawings he can share. If he does, I'll post them in this thread for future reference. If anyone saved his drawings and can post them up, that would be great.

Thank you.

DC

 

I might have his article saved on my computer.
I”ll look and post it if I still have it.

 

Hello DC3 -
I can supply You with photo(s) of Stan's with a "stock steering box".
Another "variable" You might want to consider is the cylinder-head choice.
I believe that the location of the exhaust ports are slightly different by head mfg. company?
Raised exhaust-port design?
The #-3 Pipe is VERY close to the steering-box "octagon-tin jam-nut" with my combination.
I did grind the jam nut at the offending area.
Stan's Headers AFR-180 Heads.
Please advise on how I can assist You.
Silver 7T8. (Larry)

 

Great.

Thanks Larry,

If you could post a couple of photos, that would be great.

I hadn't considered cylinder heads and their impact. I may have to figure out how to compare the heads on the new engine I've chosen with the camel hump heads on my existing engine.

DC

 

DC3
Here are a couple of photos of my Stan’s Tri-Y Header install.

My Stan's Headers are installed on AFR-180 Heads.
Raised exhaust port vs. standard head? (IE: Camel Hump)?
Most aftermarket aluminum heads have raised ports?
GM Vortec heads have raised ports?

The illustration shows a “side-view” of the fit-situation I have.
If the header is located either UP or DOWN increased clearance would result.
I worked with the fit at both the engine mounts & trans mount to get max. clearance.
Very close clearance of .095" / 2.4mm was the best result.
The engine "torques" the opposite direction under acceleration.

I am monitoring Your findings, as I am interested in the Borgeson conversion.
Lastly I am approximately 1-hour from Stan’s located in Auburn, Washington,
thus I might be able to assist next spring?
(Note: My car is put away during the “Rainy Season”)
Hope this helps.




Your Standard GM Camel-Hump would move the pipe "down", thus increasing the clearance?

 

Thanks Larry,

Appreciate the help.

Your photos give me hope. But, it's hard to tell much from photos so I can't say for sure either way.

The cover bolt on top of your gearbox that is closest to the #3 tube looks to be roughly in the same fore/aft position as the bolt on my Borgeson box. That bolt on the Borgeson box may be a little closer to the engine but with the way the #3 tube swings toward the firewall, it may not matter. The area of your gearbox that is closest to the header tube is the area on the Borgeson box where the power steering hoses connect. That area is no closer to the block than is the rag joint so it looks roughly the same as yours. Both the rag joint and that area of the Borgeson box are at least 5.5" from the engine block and might be closer to 5.75". It was hard to tell if I had my tape measure situated correctly. I'll be able to get better measurements once I move the Vette into the shop and get it up on my QuickJack.

I'm told the aluminum heads that will be installed on my new engine are closer to your AFR 180s than to my existing camel hump heads in terms of how the headers will fit.

I'll put off ordering new headers until the last minute or until I know for sure either way. I'm going to touch base with Stan's and see what they have to say about fitment. When I first quizzed them about their headers with Borgeson, they offered to test fit a set for me if I brought them my car. They also said they could probably modify their header to fit depending on existing clearance but again they would need my car in their shop to do it. That's an 1800 mile trip (one way) so not feasible for me.

It would be nice if somebody with the Borgeson setup could swing by Stan's and get a set of the Tri-Ys installed so we would all know for sure. : )

DC

 

DC3,
Contact me when You get measurements You are confident with.

Consider the following thoughts - - -
Measure from the cylinder-block head gasket seam out to steering box points.
Thus eliminating differences in cylinder-head castings from different manufactures?
( In confined areas - Maybe use straight wire pieces then measure wire lengths?)
I am guessing that You are probably working with a GM Cylinder Block?
I have a Dart SHP Block -
Just thinking out loud & trying to eliminate as many variables in measurements possible.
Let alone that C3's measure wildly inconsistent / factory tolerances / accident damage / corrosion-sag etc.
Maybe email me when You have information as I travel and can go weeks without looking at the forum.
larry.krueger@outlook.com

 

Sounds like a good plan.

Measuring from the head/block seam sounds like a good way to be consistent.
My block is a '73 counter engine GM block.

Still need to be clean up and organize the workshop. Hoping to get the Vette in the air sometime next week.

Thanks again,

DC

 

DC3, As the Australian Distributor of the Borgeson product range, I have sold a lot of boxes for Corvettes, mostly C3s. I have a friend with a '74 big block with the body off at the moment, so could take some photos. It has headers fitted and there is plenty of clearance there. His problem areas are the #7 header pipe and the clutch linkage, and the idler arm on the other side, but NO PROBLEM with the Borgeson box. Can't comment on your Tri-Y headers, but more than likely they will clear.

Regards from Down Under.

aussiejohn

 

Thanks John, I hope you're right. I don't think pics of a big block car will be needed at this point but I'll holler back if that changes.

DC

 

DC
I took some pictures and took some measurements. The measurements were more difficult than I thought due to the odd shape.

The main clearance issue I believe is exactly where you put the yellow arrow in post #11. Also at zero inch on my yellow ruler in the vette box pic. The new box is much wider there, but because of the way the bolts are clocked, most of the extra width is over the frame rail side. I'll load two top side pics and you can base your guesstimate off the pinion adjusting nut. I am not sure if it is any closer to the engine at that point, but the borgenson box presents a more vertical surface there, not round, due to the upper and lower bolts.

 

Thanks Leigh. This helps. I'm a little behind on getting into the shop and taking some measurements on the car but hopefully soon.

DC

 

Finally got to the point where I could take some better measurements. Since I was going to remove the existing headers anyway for the engine swap, I went ahead and removed them to get these measurements. Due to the angles, some of the measurements were best taken to the top of the cylinder head (just below the valve cover gasket) and others were best taken to the top of the engine block (just below the head/block joint). As best as I could, all measurements were taken from the point on the gearbox to the nearest point on the head or block regardless of angle. To make measurements easier, I used two pieces of small straight wire shorter than the dimension to be measured. I placed the wires together and held them in the middle. I then extended the wires to the points to be measured. While continuing to hold the two wires in the middle, I moved them away from the gearbox area and then measured them with my tape. For the record, the heads are old school camel hump heads and the block is a '73 counter engine small block.






A: From the case just below the head of the bolt to the top of the cylinder head (just below the valve cover gasket) = 4 - 3/16"

B: From the top of the engine block (just beneath the head/block joint) straight across to the body of the gearbox = 4 - 3/8"

C: From the case just below the head of the bolt to the top of the cylinder head (just below the valve cover gasket) = 3 - 13/16"

D: From the case, centered on the lower bolt head, to the top of the engine block (just beneath the head/block joint) = 5 - 13/16"

E: From the case, centered on the upper bolt head, to the top of the head (just below the valve cover gasket) = 5 - 7/16"



DC

 

Here's one more photo that might help others trying to sort out header fitment with the Borgeson gearbox. The existing headers were removed for the photo. The piece of wood in the photo is exactly 3.5" wide. I placed it across the header mounting surfaces on the cylinder head such that the board was perpendicular to those surfaces. The gap in the photo between the board and the Borgeson gearbox is a hair over 1/8" ( the photo makes it look like a larger gap).






DC