Mrgoodwrench3

There seems to be a lot of talk about pushrod length. I realize the only correct way to know is to measure. But I am curious to know what most are using in similar set ups. More specific I have a 2007 5.3 LY5. I plan to use the LS7 lifters with a Lunati cam. I know that these are a bit taller than stock so a shorter pushrod like the 7.350 may be necessary. I have also read others who are using the 7.400 without problems. The heads and block are stock and have not been resurfaced. Any thoughts?

viciousknid

iTrader: (8)

Also are there any other Lifters someone would recommend that are NOT taller and would allow the use of 7.4 pushrods?

jg53

iTrader: (10)

good someone was ahead of me on making this thread!!!

smokeshow

iTrader: (16)

LS1 lifters are .060" shorter than LS7. on the LY5 you'd pick up .015" of preload with 7.4s...stock rods would keep it at factory preload, theoretically.

Mrgoodwrench3

Not sure if this has been mentioned before. There seems to be a lot of references about "LS7" lifters. The same part number is used in the 5.3 from the factory. AC Delco # HL124, GM # 17122490. I do not know when the LS motors switched to this number but maybe this will shed some light into the difference in push rod length 7.350 and 7.400.

smokeshow

iTrader: (16)

my lifters are part #12499225. sad, i've actually memorized it lol

Mrgoodwrench3

Part number 12499225 is a box of 16 lifters. The individual # is 17122490 HL124. All the same parts.

smokeshow

iTrader: (16)

ah i see

03 True Fire

iTrader: (1)

ok so they were saying the stock lifters wouldnt hold to an aftermarket cam with 7.4s, thats why the ls7 ones were applicable, but using the 7.35s, but would the stock lifters hold for the usual 7.4s?

smokeshow

iTrader: (16)

you don't want to use the stock lifters with a bigger cam...they're prone to collapsing.