I have for sale 8728 box with bypass. Circuit can be bypassed in two ways one will increase revs by 300 rpms or so and will test good on test box or if chip is replaced with low rpm chip to test. But it can be detected if box is opened up. I also have a version that will test and looks stock visually inside and out. First version can be controlled many different ways including remote from the infield. price starts at $100.00 the second version cost $500.00 and includes a 8728 msd box. shipping is not included in prices. all these mods can also be done to a 6al version also.