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ANOTHER Datsun Z/LS3/T56 Swap Thread

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As the title says....I am just starting the teardown on a '74 260Z that I am going to strip, media blast, cage, and swap in (probably) an LS3 and T56 6-speed.


Here are pics of the car in its current form:










The car clearly has had some cosmetic restoration work done to it during the course of it's existence, and some have expressed to me that it is "too nice" to do to it what I have in mind.  But it really isn't all that nice.  The paint job looks OK from 20 feet, but in reality it is a cheap respray with over spray on bumper rubber, glass rubber, and many other places.  Also, the engine is just....tired...and it feels like it is putting out about 80 RWHP.  And finally, it is an automatic....and I have trouble believing that first gen Zs were even sold with autos....so out of character for the car.  In a nutshell, I have no hesitation to strip it down and start over.


The plus...I cannot find any rust...anywhere.  I think the car spent it's life in the Mojave desert.


The plan (subject to evolution) is to make it into a pure track car that is still street legal (barely).


I will try to keep regular updates.  I have just started dismantling it. 

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  • 2 weeks later...

Just a small update....been spending the past week gradually disassembling the car.  I realize this forum probably does not need more photos of dismantled Z cars, but for the sake of thread continuity, here they are.


Big job, tearing a car down to every last nut and bolt.  I have worked on cars a lot before but never a complete disassembly.  More time consuming than I expected....and I expected it to be time consuming.


So far shell looks good.  Frame rails are a bit dented and abused, but still no sign of any rust at all.


Thanks for looking.














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Just more boring teardown photos.....


Car is completely dismantled, and again I am very happy about the condition of the OEM metal.  I will have to check "rust repair as needed" off my list of jobs.  It does have bowed up floorpans from improper jacking/lifts, which I hope I can address with a 5# rubber mallet and a section of 2"X4" lumber.


Next on my list is removing all the assorted brackets/harness attachment points that I won't be using, and wire brushing off most of the seam sealer in preparation for media blasting.


Thanks for looking.











Edited by Ironhead
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  • 3 weeks later...
  • 4 weeks later...

Car is back from media blasting and has been epoxy primed.

No real surprises emerged, except it had a fairly substantial dent right behind the driver's door that had been pulled a bit and heavily bondoed.  Also the rear hatch had somehow been damaged...was all rippled....and will either need bondo or replacement when things go back together.  The only rust was the small spot (2"X2") under the driver's seat that I mentioned in my last post, where someone probably spilled a beer in 1977 or something.

Nice knowing exactly what I have to work with now, and also nice that it no longer smells like foot, ass, and mold.

Next up is carefully positioning racing shells and welding in brackets for them, so I know where to start building the roll cage.  That should be interesting since I have never bent a tube before.

There will also be extensive seam stitch welding and strengthening of the underbody rails with the Bad Dog units.

Thanks for looking.










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  • 2 weeks later...

Just working on replacing damaged or otherwise ugly sheet metal.  This is the first time I have ever done any sort of bodywork, and I was a bit apprehensive about how it would go....but so far it seems pretty straightforward.


I am spraying the back of the "blind" panels with epoxy primer before I weld them in, but obviously the welding will burn off the epoxy in the immediate area.  Any suggestions for rust proofing the resulting bare metal on the backside of the panels, since there is no longer any good way to get at it?  I was going to spray in one of the "cavity wax" products once painting was complete, or is there a better solution?


Thanks for looking.














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  • 2 weeks later...

Wow! Who did your blasting and priming? 

U-Pol weld through primer is awesome. I get it on Amazon. I was using 3m Weld Tru II but i think the u-pol is better. Better adhesion and if you accidentally weld over a little, it's more forgiving. 

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On 10/6/2017 at 11:04 AM, LLave said:

Wow! Who did your blasting and priming? 

U-Pol weld through primer is awesome. I get it on Amazon. I was using 3m Weld Tru II but i think the u-pol is better. Better adhesion and if you accidentally weld over a little, it's more forgiving. 

American Stripping Company in Sacramento.  Very happy with the work they did.  They took off all the undercoating as well....although I had to remove the seam sealer myself as it is largely resistant to the blasting process.

The only problem with having the car blasted, is getting the remaining blasting media out of all the nooks and crannies.  I still have a lot of it falling out of the frame rails, etc.  Not a major problem, but definitely annoying.  The only other alternative is acid dipping, which definitely brings with it some potential issues as well....from what I have read.  Also the closest place to me I could find that does acid dipping was in Oregon.

After blasting they used Lusid EP210 epoxy primer, which I bought a gallon of also to touch up the various areas after doing bodywork, roll cage, etc.  Great stuff....reasonably priced (as auto finishing products go), easy to spray, and super durable.

On 10/6/2017 at 1:03 PM, fluidmotion said:

Eastwood makes a paint can specifically for spraying the inside of frames.  Eastwood Item #15275Z.  When I finish up my chassis I'm buying a box of these puppies and going to town.


Yeah, my current plan is to get the car completed finished and painted, then hit all the blind cavities with the Eastwood product, and go over that with SEM cavity wax.  Sort of a "belt and suspenders" approach.

Since the car is all stripped and cleaned now, I figure it makes the most sense to apply the rustproofing products after final finishing so there is no chance of them screwing up the adhesion of the paint.


Regarding the weld through primers, I have read up about them a lot and most of the reviews have been mediocre.  There was a guy on YouTube who actually tested them on pinch welds....then left the parts out in the elements for a while.  Next he pried open the welds to see how well the primer protected the metal.  There was a lot of rust.

I guess the conclusion is that there are no perfect solutions....but I would have to agree that for any kind of lap welds the weld-through primers are about all we have.


Edited by Ironhead
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  • 2 weeks later...

"Life" has sort of taken over lately, and I haven't had a lot of time to work on the "Z".

In the intervals I have had, I decided to tackle the differential build rather than get into body work.  I picked a R200V differential from an NA 300ZX as the basis for the build, even though I initially thought with an LS3 build I should go R230.  The problem with the R230 is that the final drive is much too tall for my intended gearing and tires....redline in 6th gear (T56) would have been somewhere around 220 MPH (yes I know it would not go nearly that fast) and I could not find any available ring and pinions to change it.

Knowledgeable people told me that the R200V is quite strong and should handle the V8 swap just fine.  It comes stock with a 4.08 final drive, but via Ebay I also bought ring and pinions in 4.375 and 4.636 that were available from some sort of nameless "Japan only" applications.

I am in sort of a quandary as to which I should use.  The 4.636 would redline in sixth gear at 166 MPH, the 4.375 at 177, and the 4.08 at 189.  At 3000 RPM in sixth gear speeds would be 77, 82, and 87 respectively.

This is a track car build, that will be street driven primarily to and from track days only, so I am not hugely concerned about highway cruising comfort.  I am leaning toward the 4.375 final drive but would hugely appreciate some input from those of you who have done this.

My diff casing as received was chipped and rusty.  Can't have that can we?  So I wire brushed all the crap off, epoxy primed it, and painted it gloss black.

I was looking for a proper 2K single stage (no clear coat) paint for drive train components that would be durable and solvent resistant, didn't want to spend $600 for a gallon of Imron, and settled on Delfleet Essential by PPG.  It is a reasonably priced product, designed for commercial applications on trucks and buses that will not be clear-coated, and so far seems like it meets my needs well.  Easy to spray, good gloss, and dries very hard and (apparently) durable.

Thanks for looking.






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I'm in a similar boat and have been researching the final drive options available. I've got a abs R200 vlsd from my 180sx and an open R200 diff. I've also got a helical from an S15 Silvia sitting here as well, and can swap it into either one. Honestly, I wouldn't worry that much about 6th gear, the other 5 (well, 1-3 and 5, 4th is always 1.00) are the important ones. If you've got one of the transmissions with a 2.66 first and 1.78 second I'd use the 4.6 final.

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  • 2 weeks later...

I am waiting on parts from Japan to finish setting up the differential, so I have gone back to body work.

Despite my rosy predictions, I did come across a small patch of rust under the rear corner of the passenger side door.









I am certainly not complaining...considering the state of rot of cars that other much braver souls are tackling....but it is what it is and it had to be dealt with.  The outer rocker panel had some small pinholes where it had rusted through (that was the only way I found the issue) but after wire brushing the rust off I found the inner panel was only pitted.  I treated the area with SEM "Rust Mort", then epoxy primed all the bare metal before patching the outer rocker with new metal. 

I also found that no matter how I modified them, the stock seat mounts would not allow me to mount seats low enough to fit in the car with a helmet on (I am 6'-3").  So, I wound up removing them and making mounting rails out of 1" .120" wall square tube.  I welded M8 plate nuts inside the tubes so I would not have to fiddle about with nuts when bolting in the seats.  With the side mounts I am using, this allows the lowest possible mounting of the racing shells....the lowest part of the seat is only 1/4" or so from touching the floor of the car....just enough clearance to allow for a coat of Lizard Skin and bedliner down the road.

Being a noob welder, I found it a bit tricky welding the .120" tube to the ultra thin sheet metal on the floor of the car without constantly burning through...but gradually figured it out.

With these rails I have approximately 4" clearance between the top of my head and the roof of the car, which should be more than enough to allow adequate helmet clearance.

I have also started stitch welding the car structure....a tedious mind-numbing process that I seriously question will bring significant benefits.  I know stitch welding is controversial....and I agree with some that it may not help a thing...but since the car is completely stripped I figured it was now or never and decided I would do it.



Thanks for looking.








Edited by Ironhead
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