I came across a good deal on some new 1.6 bowtie rockers GM part number 12557779, all I know is that these where replacements sent by GM for the original LT4 rocker arms..What I would like to know, since I only have 16 individual rockers in there boxes..what poly locks and rocker studs do I need to install these on my LT1..Just want to know...I don't know if these work with the stock rocker studs..any help would be great..
Thanx..

 

i think those were made by crane for gm. if they are self aligning, then you don't need studs. as far as poly locks and springs, i switched to lt4 versions when i did my swap, but the originals will work as well.

 

Your right on the part where Crane makes them...I belive these where the replacements for the ones the lt4 vette came with when they had a recall..The rockers I have are all individuals and didn't come with polly locks which is why I'm asking which ones they would use..if it's the standard 3/8's..and yes they are the self align ones..they have the bowtie on them along with a CR engraved on them..

 

the locks/retainers will fit from stock rockers and studs. as a side note, it is widely recommended to upgrade springs as well which is why i used the lt4 springs over the stock lt1.

 

The stock stamped steel rocker hardware will not fit. Go get a set of poly locks from ARP or the like. The stck studs should be replaced as well but the stock ones should fit.

With the stock cam, the stock springs are marginal at best. You really should swap them out for aftermarket ones. The LT4 springs are not a great choice as they were originally meant to move a much lighter valve and are prone to valve float at higher rpm.

Do some research and pick a set if springs that will give you a sear pressure and an open pressure at the stock level or slightly higher that uses a double spring or a single spring with a damper.

 

just to clarify, bw is correct on the POLY lock hardware point as the stock ones will not fit, however the stock spring locks will fit.