So I'm hoping to upgrade to some Vortec heads but have a few things bothering me.

First, common knowledge indicates that roller camshafts/lifters are better for performance, more reliable, and less likely to wear. My current camshaft is flat tappet. I've been told that to convert to roller I need several things, first, the lifters will need a tie bar to keep them from rotating in the lifter sleeve, thats understand able, I've also been told that to prevent cam walk on a roller cam I'll either need some sort of retaining plate?? or thrust button? I don't get that. Help?

Second, does anyone know the max lift of stock vortec heads? A small voice in the back of my head keeps saying .425" but I don't know where I read that. I'm also hoping to get a new cam but don't want to kill the springs, I don't have a machine shop anywhere near by to machine valve spring pockets or anything like that, any help with information on the valve springs is appreciated, or any advise.

third, I've also heard that roller cams have a more aggressive lift and require a higher rate of valve springs, so as to avoid the lifter from losing contact with the cam lobe or valve with the valve seat, any advice on that? recommend springs?

Any and all help is appreciated guys, thank you.

 

The lobes on a flat tappet cam are tapered to rotate the lifters and provide a rearward thrust on the cam. Roller cams don't rotate, so aren't tapered, and there's a thrust button in front on retrofits, or a thrust plate on factory rollers to keep it from walking forward.

You can get a tool to cut your own spring pockets if you like.

Roller lifters are heavier than flat tappet lifters, so they need increased spring pressure to control their motion. Just use whatever spring the cam manufacturer recommends.

 

What would you recommend me to do for converting from flat tappet to roller?

 

Not much to recommend... pick a cam, pick the valvetrain parts to match it, machine the heads for the lift and/or springs if you need to, install it all.