A retiming may be needed also you didn't say if you were using the smart parts reg, if you are, lube the piston up as well. you can try to time it yourself but it is fiddly on the LS board, on the old board trial and error will get you sorted, way easier to get smart parts to do it. As for how much lube is too much just expirence will teach you. A fault to look for though not sure if it will cause the problem you are having is to check the piston rod cos they can get deformemed on the end and also get bent (piston rod is the long rod that falls out when you strip out the piston etc) The piston its self has a plastic ring around it when lubed it should slip in and out of the housing easily, smooth it down with some wet and dry glasspaperand re-lube making sure there is lube underneath the plastic ring. Oh Lube should be the stuff smart parts reccomends Dow 33