Twin 67 5.3?'s
#1
On The Tree
Thread Starter
iTrader: (13)
Join Date: Jan 2010
Posts: 103
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Hey guys,
Kinda curious of what yall think of this combo. It is a stock lm7 with Rob bolts an studs etc with twin 6766 billet precisions. When I set out to do the build I was planning on putting everything together with a 370 so i purchased .81 housings. How laggy do yall think this set up will be with a 6 speed? A forged 370 is in the future but for sake of getting the car running I'm thinking of just running it with the 5.3
Kinda curious of what yall think of this combo. It is a stock lm7 with Rob bolts an studs etc with twin 6766 billet precisions. When I set out to do the build I was planning on putting everything together with a 370 so i purchased .81 housings. How laggy do yall think this set up will be with a 6 speed? A forged 370 is in the future but for sake of getting the car running I'm thinking of just running it with the 5.3
#2
TECH Regular
Join Date: Jun 2011
Location: Milwaukee, Wi.
Posts: 420
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
It would be interesting to hear ppl's answers. I'm also doing 67's on a 5.3L. Will be a forged 347 eventually, but my truck is a auto and midmounts with .68ar.
#6
TECH Enthusiast
Join Date: Sep 2010
Location: North Central Ohio
Posts: 580
Likes: 0
Received 0 Likes
on
0 Posts
Trending Topics
#11
TECH Fanatic
iTrader: (4)
Join Date: Apr 2005
Location: Shelby twp, MI
Posts: 1,514
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I honestly don't think it would be to bad with the right cam and a little bit of compression.
If its just thrown together with untouched 317's and a LS9 cam or similar its going to be a roach...
If its just thrown together with untouched 317's and a LS9 cam or similar its going to be a roach...
#13
FormerVendor
iTrader: (7)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
For these junkyard engines, I think 67s is too much compressor. They'll need to spin to take advantage of the airflow, and the setups would honestly probably be faster with 6264s or 6266s due to transient boost and area under the curve improvements.
If you have good rods and pistons, and can spin 8000, then they may be beneficial, but still, 6266s is a LOT of compressor. 1400+ hp worth. Well beyond what a JY5.3 can handle. Well beyond what a 4 bolt setup can handle!
If you have good rods and pistons, and can spin 8000, then they may be beneficial, but still, 6266s is a LOT of compressor. 1400+ hp worth. Well beyond what a JY5.3 can handle. Well beyond what a 4 bolt setup can handle!
#14
10 Second Club
iTrader: (33)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
For these junkyard engines, I think 67s is too much compressor. They'll need to spin to take advantage of the airflow, and the setups would honestly probably be faster with 6264s or 6266s due to transient boost and area under the curve improvements.
If you have good rods and pistons, and can spin 8000, then they may be beneficial, but still, 6266s is a LOT of compressor. 1400+ hp worth. Well beyond what a JY5.3 can handle. Well beyond what a 4 bolt setup can handle!
If you have good rods and pistons, and can spin 8000, then they may be beneficial, but still, 6266s is a LOT of compressor. 1400+ hp worth. Well beyond what a JY5.3 can handle. Well beyond what a 4 bolt setup can handle!
#16
On The Tree
Thread Starter
iTrader: (13)
Join Date: Jan 2010
Posts: 103
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
For these junkyard engines, I think 67s is too much compressor. They'll need to spin to take advantage of the airflow, and the setups would honestly probably be faster with 6264s or 6266s due to transient boost and area under the curve improvements.
If you have good rods and pistons, and can spin 8000, then they may be beneficial, but still, 6266s is a LOT of compressor. 1400+ hp worth. Well beyond what a JY5.3 can handle. Well beyond what a 4 bolt setup can handle!
If you have good rods and pistons, and can spin 8000, then they may be beneficial, but still, 6266s is a LOT of compressor. 1400+ hp worth. Well beyond what a JY5.3 can handle. Well beyond what a 4 bolt setup can handle!
#20
TECH Senior Member
iTrader: (5)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Car came on strong low but I would say full boost in the 4500+rpm range.
![](http://i70.photobucket.com/albums/i86/V-seriesTech/jamie_tt_boost.jpg)
Above runs stopped due to lack of fuel @5800ish rpm(93 oct-12 degrees of timing-11.5psi-afr 205's-trak cam-stock 5.7 bottom end-fast 90)
Didn't DRAG/TRACK race this setup so couldn't give you a track opinion. Worked very well on the street though.
![](http://i70.photobucket.com/albums/i86/V-seriesTech/jamie_tt_boost.jpg)
Above runs stopped due to lack of fuel @5800ish rpm(93 oct-12 degrees of timing-11.5psi-afr 205's-trak cam-stock 5.7 bottom end-fast 90)
Didn't DRAG/TRACK race this setup so couldn't give you a track opinion. Worked very well on the street though.