Hobbszombie

Installing a new set of Trick flow 235 heads on a 408 with LS7 lifters. When checking pushrod length (zero lash, no preload) I am finding the intake and exhaust valves are slightly different heigths. Are You 235 guys running two different lengths of pushrods or falling on both ends of the pre load range of the lifter with one rod? Or do I just need to go to bed.

Thanks

cam75w/ls1

iTrader: (2)

I had that problem w/ my L92s when they were off the car. I called the machine shop and they said it was normal. I went ahead and installed and they have been fine so far. Only have 2k miles right now.

1-Sleeper

I know this is an old thread, but I have a similar issue with my 215's. They have been made into basically a 225, 2.055 intake valves, 1.57 exhaust valves milled to 62cc. I bought the car done, pulled the heads to do lifters and valve springs and noticed my exhaust valves are .023 , higher than the intake valves. After having 6 fulcrums cracked on my HS rockers, it's a bit concerning as to if this is the reason for it, or if they were worn... The bad thing about picking up something that someone else built or had built! It's run 9's on a 200 shot, and the top end had seen 2 motors, only one, about 10 passes and 5000 mi. with larger valves and 4" bore. Thank you in advance for any replies. I've been beating my head off the wall trying to figure out if I should put it back together and run it how it's been, or if I need to do something to correct it. I don't have the option of adjustable rockers, and don't want to buy a set!

Brian Tooley Racing

iTrader: (13)

Not only are there differences in valve height, but if the cam lift is different from intake to exhaust then the base circle on the lobes will generally be different also. We run 2 different length pushrods all the time because of this.

1-Sleeper

Thanks. I'm not sure if I understand correctly, but the heads are off of the motor. I noticed after I did the springs on the heads. How would I tell what size push rods I need, if any difference at all, just measure an intake and exhaust, add my preload for the Morel lifters and find the .025 push rod in between?