[eric32]

Hello guys I have a some questions and hopefully someone can help me out. I bought a gm 350 one piece rear main seal block part NAL-10105123 from summit racing a few months ago. Is the same block used in the 1996 and newer vortec 350's by chance or not? I am putting it together next weekend and I have read about a issue with timing chains with oem roller cams etc such as the gear hitting the front of the block to hitting the cam retainer plate head bolts. What I am worried about is the timing chain cam gear hitting my cam retainer bolt heads. I have a jegs billet steel double roller timing chain for oem roller cam and it fits on my cam right etc. But when I put my cam retainer plate on the cam and just press the gear on I have about maybe 1/8 of an inch clearance or around there but not much. I don't have the bock on an engine stand yet. So what do I do if this happen's? Dont know what type of timing chain to get if the jegs one will not clear right. I would like to use a double roller good quality timing chain set that can get reved up to 6000 rpm with out no worries. I checked up a 1997 c1500 truck with a 5.7 engine at advance auto parts and they have a double roller chain set for around 52.00 is that a decent performance chain or not? I would hate give up my jegs billet steel double roller set. Hope someone can help shed me some light.
Thanks
Eric

[ssmonty]

I don't know if your talking about clearance between the top of the screw head to the back of the cam gear rearward face or the side of the bolt head to the gear hub, and I don't know if if I described that correctly, but either way, you might look at an alternate button head bolt beside the OEM type.
The one I plan to use is stainless and has both a shorter head height and a smaller dia. and seems to clear my Cloyes double roller gear(Set PN 9-3545X9) just fine. The 1/4-20 bolt started out as a 5/8" length but I trimmed it on a grinder to get what I thought was the best length(.550"). Some may advise against stainless as its not as strong as say moly, but I'm going to give it a try.
For what its worth.
ssmonty

[eric32]

Cool nice chain set looks almost just like the one I have.Yeah what I was talking about is the top of the bolt head and the back of the cam gear. I only have a little clearance but not much. The bolt head is up a little too high. The side of the head is not a problem its fine. I will maybe try your method. I have a local hardware store that has all kinds of different bolts I will see if I can size something up.If anyone else reads is there a difference between the oem roller cam timing chains and the ones made for the vortec l31 350 block? I thought it was all the same just they changed the bolt distances from side to side on the front of the block.
Thanks
Eric

[DoubleVision]

I think you should contact Summit. they are usually more than happy to help.
If the block is based on the 880 Vortec casting then it will require a cloyes single roller "Vortec" timing set. These are avalible at Northern Auto Parts.
If any double roller set is used it`ll make contact with the block and ruin the engine rather quickly.
http://www.northernautoparts.com/Pro...tModelId=10001