Got a question:

The run down:

Installed a CC305, w/ 1.6s Magnum rockers, only gained 23 rwhp from the last dyno result (I know dyno results vary and i think this one was slightly low, but anyway, read on):

I talked to a guy I know that knows LT1s very well. He was thinking my low power gain from my cam (23 rwhp) could be from my lifters. It sounds very reasonable. Here's why....My lift is about .543" intake and exhaust, and combined w/ the higher spring pressure, and the fact the stock lifters have 99,000 miles on them....

Just sounds like they could be compressing too much and not getting the full effect of the cam. You guys think that sounds reasonable? Should I replace them with the Comp Cam OE or Comp Cam R? What are the differences in those two lifters?

This guy had problems w/ his setup too, and finally narrowed it down to bad lifters, and repalced the lifters and gained about 21 rhwp from the new lifters.

So, Should i replace them?

 

it certainly couldnt hurt if you dont mind tearing it down again... but that does make sense.. also is your running stock programming? i dont know if the 305 is too big for stock

 

It's tuned by MTI in Houston.

 

I went with new lifters when I did my LT4 conversion. Stock lifters were in excellent shape for 60K miles, but I wanted a piece of mind and not second guessing if anything went wrong.

 

I lost a lot of Upper RPM power after my Hot Cam kit install. Turns out my stock lifters were definitely worn. I replaced them with Comp Cam R lifters and i definitely noticed more upper RPM power. New lifters also reduce the possibility of valve float.

 

Just did my 383 and the engine builder said the stock lifters are fine. I figure since they were in the business of making money...if they werent he coulda easily have sold me some.

 

id replace them....those may be fine but will wear out soon....get you some hydro lifters that will be capable to maximize the lift out of that cam

 

I would replace them. When I originally did my motor I skimped out on lifters and ended up collapsing 3 of them on a dyno.

 

Most cams are available with a matched set of lifters. Lifters should always be changed with a cam swap, this inssures even wear between the lifters and cam, and prevents premature failure.

 

I left my stock lifters in with no problems whatsoever. Just dynoed at 338.9 to the ground.

I wouldn't necessarily say replace em. I would check em, clean em up, and put them back in assuming they are okay. These are roller lifters, they don't develop a wear pattern like the flat tappet lifters, so you should be all right.

Just my .02

 

How many miles did your lifters have on them dubby? That seems to make a large difference as well. Mine have 99,000 miles. I have heard that if you have less than 70k miles, yuo don't really need to change them, but above 70k it is recommended. From what people are posting here it seems like a fairly good idea to swap my 99k lifters out with some new ones.

 

replace them with some comp 875's

 

Well I had 62,000 miles on mine and they collapsed so I would not go by the above.

 

I did the cam change at 72,000 miles...I have 76,000 on the car right now.

 

99,000 miles! Geez, replace those lifter. Don't take any chances.