'70 #s RS/Z, Orange on Black
 

This looks like a good car - sounds like it has had the trunk pan replaced...and was sold new in NJ so that's not too much of a surprise. No docs, unfortunately, but the drivetrain stamps look OK to me.

Link to 1970 RS/Z auction

https://i.ebayimg.com/images/g/P9kAA...Zc/s-l1600.jpg

https://i.ebayimg.com/images/g/X-gAA...bo/s-l1600.jpg

https://i.ebayimg.com/images/g/7yEAA...cI/s-l1600.jpg

124870N515506

Is that passenger side front fender correct for this year car?

No the indent identifies it as a later replacement fender.

----I don't know 70's well. Add states that the car may have been correctly converted to an RS. Would that have anything to do with fender replacement?.....Bill S

No. Fenders are the same from RS to non-RS. Everything in front of the fenders changes.

“Correctly converted” but missing the chrome edging on the top of the fenders and hood that a true RS would have.
Not sure how a first week of March build car has third week of March original heads? EDIT: It looks like the heads are cast B 18 for second week of February. The sellers description lists 3 18 so a good chance those are the correct heads.
Looks like a nice car but would definitely warrant a close inspection IMHO.

This is my old car. It was a real original drivetrain Z that I found sitting in early 90's with 50k miles and 1975 inspection. Second owner bought car in 71 in New Hope pa. I converted Rs nose and tailights with NOS sheetmetal. I had the door and hood RS moldings but did not install them as the RS doors have factory studs and I was scared to scratch the hood.
It had original paint but was rough. I painted car myself and did a frame on detailing. Buried the stripes under the clear coat. Car won 1st place every show entered, but far from concourse. Still have a bunch of trophys. Car was 98% original when purchased. Was missing smog, battery only when I bought it. Still had all original clamps, wires etc.. even exhaust. Had cragars. guy had original wheels, but wanted more $$ so i did not buy them. Who knew back then ? ( I do still have the original spare rim and tire though that has never been used on the road..stilll has little tits)
Interior was original with everything working including am-fm and reverse lock out and door buzzers. Was all original but I replaced the carpet and rear package shelf only.
I owned car over 20 years and drove it only a few thousand miles.
Car had original QP's and floors. I bought all new GM weatherstrips, grills, marker lights, trim etc. soon after purchase then stored car over ten years before painting it. The trunk had very minor scaling but i did not replace that at the time i sold it.

350 solid lifter...hugger orange white stripes... M-21, 4:10 posi... i had to put the correct split bumper set up on her !!

This is one car i really miss. Love shifting that LT-1 at 6000 rpm's !!

( I do still have the original spare rim and tire though that has never been used on the road..stilll has little tits)
For sale maybe?

Nice car , love the color

I actually have two original never been used 70 Z spares (rim and tire). From this Z and another from another Z that is even nicer. I’d consider selling. PM me if interested and I can dig them out.
It’s been years since I’ve looked closely at them.