yello620

You are fighting a losing battle messing with that caliper piston. Just remove the caliper and use it as a core at the parts store to get a replacement. Even if you did get the piston to move back in, it will just stick again in the future and cause more problems later. I have no idea what you are talking about with a "spacer" at the piston. Never seen a "spacer before except in some custom "race" stuff. Are you just talking about normal pad shims?

Any chance of getting pics of the calipers mounted on the car front and rear. I don't think that you have a master cylinder seal issue. I can think of three easily possible issues. Master cylinder pushrod length. Make sure it has some play in it as Mike mentioned. Generally, adjust as long as you can freely install and remove the pedal attachment pin. Rear caliper bleeder orientation. Could you unbolt the caliper and use the gravity method for bleeding and just tip the caliper around a little pointing the bleeder more towards up? I have had to do this before on a conversion that changed the bleeder position from the stock(280zx) position. Rear caliper parking brake adjustment. This depends on what year/style calipers you are using. This comment will not apply to early 280zx calipers, but the late calipers will be affected by this. The rear caliper pistons will retract far enough to give you a pedal that needs pumped up each time if the parking brake arm is not actuated repeatedly also. I have no idea really how to explain it though. Take a look at how much clearance you have between the pads and the rotor on all pads, inner and outer, top and bottom. They should all appear to be touching the rotor with basically only enough clearance for the rotor to turn.

Post a pic of the one you are looking for. I believe that there were two different styles. I memory serves correctly, 75 is about the year that they changed. And I might have one too.

Any chance that there was an error in your testing method? Or an inaccurate guage? Truck will do 90, just don't believe compression, tuning issue - yes. Most common thing to miss when doing a compression test is to make sure that the throttle body(carburator) is open so that the cylinder can get air. The cyclinders can only compress the amount of air that they receive. I think that the next thing would be the number of revolutions the motor is spun for the test. I was always told ten revolutions, but it usually maxes out around five revolutions IF you have pulled all the spark for the test. You could also have valves way out of adjustment causing low compression.

Ratsun Classifieds :rofl: Sorry to hear of this unfortunate dealing with Adam, all my dealings with him have been positive. But, they were also all in person.

I'm pretty sure that my neighbor would be getting handfuls of seeds to anything that could possibly grow thrown over the fence. He might not have a plum tree to deal with, but there will be plenty of other stuff for him to take car of now. :devil: Possibly followed by fertilizer to make sure it grows. B)

My bet is on wrong calipers. With the pistons pushed in all the way and stock thickness rotors, there will be 1/8"+ of clearance between the pads and rotors until you pump the pedal a couple of times to get the pads touching the rotor.

Probably better re-check your math on those conversions. You only got one out of three correct. And I agree, SAE u-bolts do not matter. I bet that the only way that you will get metric u-bolts is to get them made in a metric country.

We are still missing a piece of the puzzle. What size tire are you running? You might get away with 3.73's IF you ran a really small tire, but that it.

Super clean 620 you found there. Sounds like you started with 620's about the same time I did. Think I got my first in 87. I'll just leave this here. http://community.ratsun.net/topic/36703-the-bmx-bikes-of-ratsun/

Only if they are painted to match the hood.....

Your probably going to want a F-body oil pan for that conversion. It is one of the shorter(depth) pans that GM offered, and you are going to need that minimal depth to get that motor in the chassis without the pan hanging under the crossmember. The Fbody pan fit in my C10 perfectly. That 5.3 will be absolutely stupid power for a 720. Enjoy.

Those are the factory harness grounds, and on the core support between the battery and radiator is the factory spot for them.

OK, you got me, I would yank that TBI off of there too. But I still wouldn't put a carburetor on it. I would put a Nissan multi-port manifold on it and inject it. Absolutely hate carbs. I think that a fuel injection manifold looks cleaner than a carb. The fuel cut is in your tuning, and is there for a reason.

The VG fits really nicely in a 620 engine bay with ZERO cutting of anything on the truck except a hole in the firewall for the fuel injection harness. Why anybody would throw away the injection and put a carburetor is absolutely beyond any thought process. My VG620 conversion build thread is linked in my signature. Feel free to ask questions.