Hopefully, I'll be getting a LBZ motor soon and converting my truck. Once I have the motor and electronics in and working right, I plan on pulling the motor and putting the heads on my LLY block so I can "take my time" building the shortblock using the LBZ block, crank and cam. What's the minimum I'd have to do to the LLY block to move the LBZ pistons and rods into it? The reason I'd like to do that is I MAY have a shortened rod or two, and I'm planning on cut & coated LB7/LLY pistons, so why spend $2300 (give or take) on new stock Cut & coated pistons when I could likely spend a few hundred having mine machined assuming there's nothing wrong with them? I don't want the truck down while I build the LBZ shortblock, and I don't want to crack a piston in the LBZ block and risk killing it.
Changing Pistons & Rods
- Thread starter Cougar281
- Start date
No one has any thoughts? I'm picking up the LBZ Wednesday, and will probably swap it in within a week or two. From there it'll probably be a few weeks until I swap heads around.
Just so I got this straight. You want to put the LBZ motor in to get the truck running. Then pull it out and put in your old LLY with the LBZ heads, pistons and rods. Then build the LBZ block to swap back in at a later time. Forgive me, I'm a little tired. I'm sure you already know you will also have to swap in the LBZ reluctor wheel to the LLY block when you do the switch. I'm just trying to get your plan straight in my head. 
Edit: From reading more of your post you may need new rings for the LBZ pistons since they're going into a different block, and the LLY block may need to be honed? I don't know. I think Trent swapped rods and pistons on his truck without pulling the crank. Hope this atleast gives you some ideas, I'm a newb when it comes to this kinda stuff.
Edit: From reading more of your post you may need new rings for the LBZ pistons since they're going into a different block, and the LLY block may need to be honed? I don't know. I think Trent swapped rods and pistons on his truck without pulling the crank. Hope this atleast gives you some ideas, I'm a newb when it comes to this kinda stuff.
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You will have to swap cranks shafts and all bearing should be replaced then main bolts flywheel bolts all the rod cap bolts need head gaskets one way or the other. The lbz will live for awhile mine took a hard 31,500 to break and I was trying almost big turbo also had alot of bottles thru it. Held 580 rwhp for some time til see cracked a piston.
ColdLBZ, yes, that's the idea, and Tom reminded me indirectly about the reluctor. Originally I was thinking just put the LBZ heads on the LLY longblock and not swap any part of the rotating assembly. Might stay that way.
Thanks Henry. Maybe it would be better to leave the LLY shortblock as is (except the reluctor) and find another set of LB7/LLY pistons to have machined rather than pulling it all apart. I want to keep the LBZ crank out for the build.
Thanks Henry. Maybe it would be better to leave the LLY shortblock as is (except the reluctor) and find another set of LB7/LLY pistons to have machined rather than pulling it all apart. I want to keep the LBZ crank out for the build.
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