Gen VI lifter type, push rods, and retainers
 

Looking at ordering this cam kit from Hardin Marine
https://www.hardin-marine.com/p-1159...ifter-kit.aspx

I am changing from the tiny 330hp cam to something like this, and I am going to an adjustable valve train with Comp Ultra rocker arms
Hardin says even though I have a Gen VI, which does not need lifter tie bars, that they give you that type of lifter anyways in the kit because higher lift cams can have issues with the GM factory spider retainer. I would prefer not to use the the tie bars, more rotating mass, but is this an issue on a cam that only has .600 lift?

My heads are going to be ProMaxx 290s

The appeal of this kit is it includes pushrods, which may make it easier since I have never measured pushrod length before and don't want to screw that up.

Anyone used this Hardin kit before?
Thanks

try reaching out to ph1971 here on OSO, he has had some very interesting experiences with these lifters. Ask him for the photos. Also check spring pressures in this kit.
Good Luck

GM original dogbones Works great Even above 0.600" lift. I used These ifters on My Old combo, 0.375" lobe lift, approx 0.650" @ Valve. My ny cam IS custom comp cams 240/245 @ 050" with 0.385" lobe lift, and The designer Said i could use The same GM lifters But suggested Johnsson lifters, wich IS use now because i knew My engine Would Peak at 6000rpm or above and i need More spring pressure that GM lifters could take. IMO under 5500rpm and 150/370lbs springs you Are fine with The GM lifters. Have read from here that few Have used These with Crane 741 with good results, maybe someone can confirm.

The story about the dog bone style lifters from Hardin is BS, their just trying to sell more product. Im running way more then .600 lift with this style...........you need to have the lifter bores checked for proper clearance

Factory Gen VI rollers are good to 0.630" lift.

400 lbs on the nose is the limit. Valve weight largely determines spring requirements at intended rpm.

You have to watch some of the exhaust valve weights when using the extrem duty exh valves. They're often heavier than the intakes.

I run .635 lift with oem retainers/spider and it's fine.

When the roller is on the base circle, how much of the lifter is still in the 'dogbone'.

I have some take out cams, MHP-300, lifters, push rods, stock bore pistons and springs from a HP500 Carb motors. Pm if interested.

im curious do the GEN VI 500hp motors have the dog bone style lifter ?

later

yes