Just a quick question, (sorry if its a dumb one) I was just wondering, can you put a 383/402/408 rotating assembly into the 5.3l lm7 block? I just was wondering so I know if I need to go with a new block or not. Thanks a bunch guys

 

pretty much you can only bore/stroke these out to a 347ci/350. imo it wouldnt be worth it and it probably would be best to step up to a 6.0 block so you can bore/stroke it to 383-408. are you going for a n/a motor or any power adders? if power adders are used try to stick with a 4.00" stroke for maximum realiablity.

 

You can bore and stroke that block to accomplish a 383ci engine (3.90x bore and 4.0" stroke). Most people don't do it just because that ALOT of boring (over .120"), and they don't feel comfortable with that. But it has been done with success numerous times. We typically encourage people to go ahead and get into the 6.0L iron blocks if the weight is not an issue because they are very inexpensive and the extra bore size of 4.0" really opens the doors and potential for cylinder heads on your combo!

Let us know if we can help!

 

thanks for the info guys, I guess I'll just keep saving. I'm planning to do a high compression 383 or 408 (its going into my 93 rx7) maybe i'll try for an aluminum block since it be lighter.