5.3 to 5.7 
needfacts! 5.3 to 5.7
Thread Starter
Teching In
Joined: Sep 2011
Posts: 3
Likes: 0
From: houston tx
needfacts! 5.3 to 5.7 ok i have been up and down this forum and on google and other forums but
i have a 5.3 out of a 06 tahoe from wat i was told according to oter forums and articals it is possable to bore a 5.3 to 5.7 then agin i find a same amount of info to not do tht soo if some one could plz show me some solid facts with pictures of 5.3 bored to 5.7 success build thread or somethin or some one who has don this recently ad has no problems this is all i need to no as of now thks
i have a 5.3 out of a 06 tahoe from wat i was told according to oter forums and articals it is possable to bore a 5.3 to 5.7 then agin i find a same amount of info to not do tht soo if some one could plz show me some solid facts with pictures of 5.3 bored to 5.7 success build thread or somethin or some one who has don this recently ad has no problems this is all i need to no as of now thks
TECH Fanatic
Joined: Jul 2010
Posts: 1,756
Likes: 4
From: Maryland
If its an iron block, then yes, you can make a 5.7 from a 5.3. Realistically, why would you want to? The 5.3 is pretty stout and should make about the same power as a 5.7, there are guys that have been running bone stock 5.3 motors with turbo's making 650 whp...for years. IMO your money could be better spent building up the 5.3.
If I went to the trouble of boring out a 5.3 iron block to a 5.7 bore, I'd probably install a 383 stroker rotating assembly.
All iron 4.8/5.3 blocks can be bored to a max of 3.905 (same max as LS1/LS6) and most aluminum 5.3 blocks can handle that bore as well.
http://www.youtube.com/watch?v=J_PyxsR73ug
http://www.youtube.com/watch?v=J_PyxsR73ug
TECH Fanatic
Joined: Jun 2011
Posts: 1,343
Likes: 8
From: Katy, TX
There are dyno charts of 5.3s compared to 5.7s and they are so close it's not funny. The 4.8 and 6.0 are at the other ends of the power spectrum but the 5.3 and 5.7 can be withing 5hp of each other with the same heads/cam/intake.
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My point is that unless the tune or heads mismatched etc in a 5.3l bored to a 5.7l the 5.7l would have to essentially make more HP than the 5.3L!
No replacement for displacement.
*NOTE* the HP ratings are in a different RPM range. That is why usually it is useless data to compare 2 engine's HP rating since it is basically comparing apples to oranges. You have to take into account what RPM you will be operating in, especially for towing applications. Who wants a 350HP engine putting out 350hp at 4000+RPM to tow with?
Instead of rebuilding the 5.3L, the added cost of boring to the 5.7l would be new pistons/rings (assuming the 5.3L didnt need them anyway), machine work and decent set of heads. (799,243 or aftermarket). Evrything else involved you would do with rebuilding the 5.3l anway. IE: gaskets, bearings, cam, etc.
BTW I have one of my salvage yard 5.3L's in the garage tore down and will be built over the winter to go in my 85 vette. The other 5.3l will get the 5.7l treatment also and eventually end up in my Sierra.
If you got the money to blow, sure go get a 6.0L or whatever floats your boat....but those 5.3l's are a dime a dozen and can be had all over the U.S. Im going to pick up another one or 2 to stash in the garage. My riding mower may need repowered sometime down the road. ha
On The Tree
Joined: Aug 2004
Posts: 145
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From: El Paso, Texas
doing the research for the same... I know, it's been quite a while since the last post on this subject so please forgive the timing of this reply, but how has the 5.3 to 5.7 held up? I am planning the same build up for my ride and have the pistons, con rods, LS1/6 crank, and a couple other goodies that I got for a really good deal. I also plan on supercharging in the future and my engine build suggested the iron block over the aluminum LS1.
TECH Fanatic
Joined: Jun 2011
Posts: 1,343
Likes: 8
From: Katy, TX
I have over 3k on mine right now. I realize its not much, but if there were any issues with the block I think they would have surfaced by now.
Note: it may be more cost effective to start with a bare 6.0 block. The cost to bore the 5.3 out can get expensive.
Note: it may be more cost effective to start with a bare 6.0 block. The cost to bore the 5.3 out can get expensive.
On The Tree
Joined: Oct 2012
Posts: 166
Likes: 0
From: Houston
