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FirstGen · 04-18-2005, 04:08 PM

5.3 is considered a LS1 although technically it is only a Gen III motor. They do share almost everything that the 5.7 does excep for the bore and aluminum block. You can bore the 5.7 to 3.90" and put the 5.7 pistons in and you have the exact motor with a iron block. Stroke and rod length are the same.

Go with the LS1. Not knocking the LT1's (owned them in the past) but the LS1 have a far superior head/intake design (12 degree), not to mention the PCM is almost 40 times faster, better ignition, and a better cooling system (not reverse flow). With a good cam and good exhaust expect to see 350+ rwhp. It takes virtually every bolt on to make that power in a LT1...

They are just extremely effiecent motors. I made 452 rwhp and 422 rwtq which is 529 flywheel horsepower and I recently got 19.7 miles to the gallon going to Austin and back this weekend! I was cruisin at 80 MPH the whole time when I got those numbers in 6th gear.
Good luck!

Search for "LS1/T56" for my thread on my install...

04-18-2005, 04:08 PM	#4
FirstGen Just Don't Stop! Join Date: Feb 2004 Location: Dallas Posts: 1,239	5.3 is considered a LS1 although technically it is only a Gen III motor. They do share almost everything that the 5.7 does excep for the bore and aluminum block. You can bore the 5.7 to 3.90" and put the 5.7 pistons in and you have the exact motor with a iron block. Stroke and rod length are the same. Go with the LS1. Not knocking the LT1's (owned them in the past) but the LS1 have a far superior head/intake design (12 degree), not to mention the PCM is almost 40 times faster, better ignition, and a better cooling system (not reverse flow). With a good cam and good exhaust expect to see 350+ rwhp. It takes virtually every bolt on to make that power in a LT1... They are just extremely effiecent motors. I made 452 rwhp and 422 rwtq which is 529 flywheel horsepower and I recently got 19.7 miles to the gallon going to Austin and back this weekend! I was cruisin at 80 MPH the whole time when I got those numbers in 6th gear. Good luck! Search for "LS1/T56" for my thread on my install... Attached Images __________________ 1968 C10 build in process TT LSA/6L90e/9" Last edited by FirstGen; 04-18-2005 at 04:13 PM.