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Old 02-18-2012, 11:31 PM
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Quote:
Originally Posted by 1969chevyss
Hey guys I have a 355 short block with a xe268h cam stuffed in her. I have a set of vortec heads that I will get new springs to accomodate the extra lift. My question however is this, are there any other good lifters besides the ones that comp cam recommend(812-16) that will help me prevent the chances of my cam going flat. I have been doing a lot of reading and this seems to be a reaccuring problem with this grind. My next question is for my vortec heads, what sprints can I use that will drop right in without any machine work. I read that z28 springs from northern for 525 lift will work, just would like to get you guys opinion on the matter. Thanks in advance.
the springs are not the lift limit issue. The valve guide boss to retainer clearance, is the issue for more than stock valve lift.

many of the `Z/28`style stock diamete4r replacement hi perf springs will fit the vortec spring pockets if you remove the inner damper.

But you still have to deal with the retainer to guide boss clearance.

GM LS motor Z06 springs and comp 787 retainers can be used.
again verify retainer to boss clearance.

ComP cams extreme failures. Use high quality GM hyd lifters.
Use a oil additive high in Zinc and moly dysulfide
Zddp and or Moly slip and or GM EOS.
Order a custom grind comp cam version of the XE268 Say on a 108LSA instead of 110.... much better cam grind and finish quality when done in house.
( you`ll probabily make a bit more power too. )
Buy a Isky Mega cam instead. I find them much better quality.
( you`ll probabily make a bit more power too. )

Isky cams are made in house. I find the Isky stuff high quality and the flat tappet stuff lives.

Comp sells way more of these XE268H-10 cams than they can make inhouse. Who knows who is doing their high production contract work.

The GM Heavy duty `taxi `hyd lifter with the special alloy face is the best production SBC hyd flat tappet yu can buy.

Aparentl;y back in production I don;t have a current GM part number for you.

I have a comp XE284H-10 cam in my car and so far no issues. Proper break in procedures and zinc-moly oil aditives are a big help. My cam was made in house for me, at Comp.

Comp offers a extra cost cam lobe hardening treatment `Nitriding`that is said to offer better flat tappet cam endurance and run in.

Call them.
www.molyslip.com
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