Hey guys, first thing, I had to create a new account, I'm really not totally new to the forum.

Onward to the post!

I have a built LQ9 from texas speed that I am putting back together after a maggie intercooler broke and caused some serious headache.

I am putting together the valve train right now and I need some help figuring out tolerances and whether or not anything is going to break.

The old setup that worked flawlessly on my LS1: ported 241 heads, crane gold 1.8 rockers, crane pushrods (7.25 I believe), crane dual valve springs (titanium retainers, etc), crane hydraulic roller lifters (stock replacement), MTI Stealth 2 cam (224/220 .581/.581 116 LSA).

The new setup: all same parts as above, just moved onto 317 heads.

Problem that occurred recently: Recently, I had put stock rockers and stock pushrods on the 317 heads. Everything else stayed the same. The car did not like that combo, 1 push rod bent, 1 rocker arm bearing broke and 1 lifter top collapsed. Obviously something went wrong... the only big difference I could see was the stock push rods were noticeably longer than the hardened cam pushrods that came with the 1.8 rockers.

Why I used stock parts: While in the midst of moving garages, I was waiting on parts that had not arrived, so I was forced to put together a 'stock' head/valve train in order to get the car up and moved.
I had the parts so it wasn't a big deal at the time.

Question: Was the breaking of the stock parts some freak incident or were the tolerances so far off it caused a break. Should I be worried about using the 1.8 rockers and 7.25 pushrods on the 317 heads with a stealth II cam? Do I need to change the pushrod length?


Thanks a ton guys, there is a wealth of knowledge here, hoping someone can point me in the right direction.

 

People generally do not use 1.8 rockers with aftermarket cams.

 

7.400" pr in place of the original setup at 7.25"??