Stock 5.3 Truck Heads VS. Stock LS1 Heads
#1
Teching In
Thread Starter
Join Date: Apr 2009
Location: Tonawanda, NY
Posts: 31
Likes: 0
Received 0 Likes
on
0 Posts
Stock 5.3 Truck Heads VS. Stock LS1 Heads
Stock for stock what head is better or worse and why? I have been searching the forums but it seems that most people port them. I have a set of stock 5.3 heads (06 Tahoe) and a set of stock LS1 heads (98 Vette). I read somewhere that they have the same flow numbers stock but the 5.3 heads will bump the compression. My questions....
How much will they raise the compression?
Which flow better?
If you had both, and no money to port them, which would you use?
My plan for this motor is to toss it in the Tahoe, cam, headers, tune, done.
Thanks for any input.
How much will they raise the compression?
Which flow better?
If you had both, and no money to port them, which would you use?
My plan for this motor is to toss it in the Tahoe, cam, headers, tune, done.
Thanks for any input.
#3
TECH Fanatic
iTrader: (1)
1) 98 LS1 heads should have a perimeter bolt pattern
2) what engine are you building a 5.3 or a 5.7?
3) what do you hope to do with the truck when its done (driver, tow vehicle, etc)
Flow differences between the heads should marginal, with a slight edge going to the later heads due to changes in the casting methods.
Compression differences will be the biggest thing. LS1 heads have 67cc chambers compared to 61cc for 5.3's. A 5.3 with LS1 heads will drop the compression below 9:1 and lose power. A 5.7 with 5.3 heads will push the compression over 11:1, probably not the best scenario for a heavy truck, especially if you might still tow anything.
2) what engine are you building a 5.3 or a 5.7?
3) what do you hope to do with the truck when its done (driver, tow vehicle, etc)
Flow differences between the heads should marginal, with a slight edge going to the later heads due to changes in the casting methods.
Compression differences will be the biggest thing. LS1 heads have 67cc chambers compared to 61cc for 5.3's. A 5.3 with LS1 heads will drop the compression below 9:1 and lose power. A 5.7 with 5.3 heads will push the compression over 11:1, probably not the best scenario for a heavy truck, especially if you might still tow anything.
#4
Teching In
Thread Starter
Join Date: Apr 2009
Location: Tonawanda, NY
Posts: 31
Likes: 0
Received 0 Likes
on
0 Posts
The head casting number on the LS1 heads is 806 and they are perimeter bolt. I am building the LS1 to take some weight off the front of the truck. The Tahoe is a Z56 PPV that I am not going to be doing much towing with if any at all. I plan on making it a quick and fun to drive DD, that may see the track a few times.
Thanks again for your input.
Thanks again for your input.
#6
11 Second Club
iTrader: (20)
Join Date: Oct 2006
Location: Virginia
Posts: 3,131
Likes: 0
Received 0 Likes
on
0 Posts
www.smokemup.com
do the 5.3 heads.....flow is damn near the same even with the smaller intake valve....and you get slose to a point in cr....the higher cr is what you want in a heavier vehicle...it makes for better tourqe....
do the 5.3 heads.....flow is damn near the same even with the smaller intake valve....and you get slose to a point in cr....the higher cr is what you want in a heavier vehicle...it makes for better tourqe....
Trending Topics
#8
Teching In
Thread Starter
Join Date: Apr 2009
Location: Tonawanda, NY
Posts: 31
Likes: 0
Received 0 Likes
on
0 Posts
#15
11 Second Club
iTrader: (2)
4 dollars per to remove all 8 pistons, a few bucks each to hone the pin bores
and another 4 x 8 to reinstall on the 5.3 (6.098") rods. I'd guess around 100
dollars total not to mention the pistons will weigh different by as much as 20
grams and this could throw the crank out of balance.