LS blocks

[232_ray]

Sorry if this seems like a stupid question or if it’s been answered before but I’m trying to figure out if/and/or which LS engine blocks are the same as in overall mount up / size?
my problem is I originally had a cracked LS7 block to mock up my engine and trans set up. The shop that had my car supposedly finished all the trimming and whatever they needed to fabricate the new firewall for my car. I picked up the empty block and trans took them home sold the block. That was about 2 years ago. Fast forward to present times I’m frustrated and want my car back since that shop hasn’t done anything with it and now I have a car with my firewall FML!! So I now need a mock up block and trans. I have the bare case trans but need a block. So my question really is can I find an old blown up LS2/LS3/LS1/LQ? To install in the mean time for the mock up cut and trim and install of the firewall panel?? I do have a short block LS7 that’s being built for the car but don’t want to install it because of the weight and ease of shifting the block around. Any help would be appreciated. Thanks.

[badazz81z28]

Sorry if this seems like a stupid question or if it’s been answered before but I’m trying to figure out if/and/or which LS engine blocks are the same as in overall mount up / size?
my problem is I originally had a cracked LS7 block to mock up my engine and trans set up. The shop that had my car supposedly finished all the trimming and whatever they needed to fabricate the new firewall for my car. I picked up the empty block and trans took them home sold the block. That was about 2 years ago. Fast forward to present times I’m frustrated and want my car back since that shop hasn’t done anything with it and now I have a car with my firewall FML!! So I now need a mock up block and trans. I have the bare case trans but need a block. So my question really is can I find an old blown up LS2/LS3/LS1/LQ? To install in the mean time for the mock up cut and trim and install of the firewall panel?? I do have a short block LS7 that’s being built for the car but don’t want to install it because of the weight and ease of shifting the block around. Any help would be appreciated. Thanks.


All GM factory LS blocks are the same dimensionally.

[raustinss]

Ok so I was 90 percent sure that was the case but, was afraid to answer . I was afraid some keyboard warriors would slaughter me lol ... although I'm sure the ls4 fwd is a little different but it's the evil step child that nobody likes lol

[Schwartz Performance]

Yup both of the above guys are correct if you needed reassurance! :)

-Dale

[raustinss]

Oh god right 2 times in one day ... I'm done ...gimmie a beer . Thanks Dale

[Sbeck09]

I'll also say that the plastic mock-up blocks are FANTASTIC for this exact purpose. You can usually find someone selling one used or that will "rent" it to you. If you are just trying to get the basic mounts done with minimal hassle it's the nicest option. Everything is designed to bolt on, including a transmission.

[jat5150]

Glad you were able to get your question answered, I know it can be hit and miss on forums.

Quick question, where are you getting your LS7 built? I have a LS7 that I spun a bearing on and need to look into having someone rebuild it. Also if you don't mind sharing the cost of the rebuild, that would be good so that I know what I am potentially getting into.

Thanks

[232_ray]

Well I bought a built short block from another member from this forum but lost the paper work/details. Was going to have a friend run thru it and finish building it. So dat I’m in it about 8k with a set of heads I night and had west coast cylinder heads re port them and put them together