Hi, I'm getting my heads rebuilt, and wanted to know if LT1 Springs are good to use with my XE268 camshaft in my 305.

Any info appreciated.. thanks

 

I would say yes. I have "Z28" springs on the 305 heads on my girlfriends 350 which also has the 268 extreme cam, plus I've got 1.6 roller rockers on there, so the lift is well above .500. We rev it to 6K quite often and the motor sounds great so far . I think the LT1 springs would be similar to the "Z28" springs, perhaps better???

 

No. It's a risk not worth taking. Get the right thing and be safe.

Have you ever seen the insides of a motor when a valve spring broke and fell into the cylinder at speed? Let's just say, valve fragments being made of steel, they are incompressible, and they are harder than both pistons and head castings.

Just because one guy hasn't has his blow up on him yet, doesn't mean it's a good idea.

 

buy the springs to match your cam and trash the factory rotators and use aftermarket retainers.

 

Thanks guys.. Ede, are the stock rotating retainers really that bad??? they are only on the intake valves right?? Getting new comp cams retainers are going to push me over my budget .. ($125AUS) .. But I trust your judegment, and am currently looking for the right ones for my stock 305 heads.

 

The LT1 springs are good to .480 lift or so I believe. Go with LT4 springs if anything, they're good to .530 lift.

 

DON'T use the lt1 springs, or any spring from gmpp or k motion buy a set from comp to match your cam, or lunati. personally i prefer lunati stuff but most people don't. yes the stock rotators are that bad, trash them or take them to the recycle center.

 

Ok, Thanks Ede will take your advice.. ordering new comp cam retainers/locks/seals and springs

Stock valve stem size is 11/32" right? and spring is 1.250" diameter?

Thanks