Is there an intake that will fit on the Mopar Performance stage 6 heads that will work on a RB block without the spacers?

yes there is.... the 4500 series one which I ran, and I'm pretty sure there was a 4150 version.

Thanks guys I see the 4500 series is still available

They offered the Stage VI RB intake in both standard and MW port options. The 4150 version wasn't a very good design out of the box and the one I tried required a LOT of plenum reworking by an intake specialist to make it usable. If you're looking into the 4500 version, you're better off.

I've seen them on here from time to time for decent prices, I'm going to grab the next one I see.

results may vary..... I always had a pretty decent 60 ft time 1.36-1.39, respectable 1/8th numbers, but while I'd cover many cars in the 1/8th, they would drive around me on the top end. Even swapped from my 4.10 to a 4.56 gear with very little change. Finally bought the 4500 intake and an Ebay Carb Shop 1050 and slapped it on...... BAM! four tenths and 4-5 mph gain in the 1/4. My trap rpm went from 6400 to 7200.... put the 4.10 gear back in and went even quicker....mainly did it to get the rpm back down to a more "happy" level. The 4150 M1/spacer and holley 850 4150 carb were a definate cork in my system. This was a 4.15 stroke, 13-1, ultradyne NF69 mech cam, stage VI heads not max wedge ported by Dwayne Porter (info on them in the archives). Mild combo that was very easy on parts.

Click on the attached chart.......then go all the way down to the 3rd from last (P4876127). I found one 2nd hand, but never bolted on a motor, by doing a google search. It showed up on Craigslist.

The intake ports are pretty small as cast, so you'll have to open them up to your cyl. head size.

https://www.monicattichrysler.com/comersus/store/inetsolution_chartView.asp?r=19

Here is possible source.....

https://www.monicattichrysler.com/comers...?idCategory=167

Here's one if you're into a 4150 with Max Wedgie ports..........

http://www.ebay.com/itm/MOPAR-PERFORMANC...ed2&vxp=mtr

I run the 4150 with a adapter and a 1050 4500 carb. The intake has been ported but it was this way when I bought it. I wonder if I went to the 4500 intake if my car would pick up at all.