Which cam for 5.3/4-speed Snotty street motor
04-18-2015, 03:53 PM
#1
Teching In
Thread Starter
Join Date: Oct 2013
Location: Castle rock Colorado
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
Which cam for 5.3/4-speed Snotty street motor Hey fellas, I've got my 5.3 torn down to just the block with rotating stock assemble still in it. The heads are off and have a few broken bolts stuck in the exhaust manifold holes, so I think I'll buy a rebuilt set of heads instead of build these. I want to overhaul this motor before sticking it in my 1973 camaro.
Looking for suggestions on the right cam
Stock 5.3
Stock heads
Ls6 intake with injectors
Hooker headers
Muncie m-21 close ratio
Dino tune when done
Just a Friday night snotty street cruiser
Any suggestions would greatly be appreciated. Thanks
Looking for suggestions on the right cam
Stock 5.3
Stock heads
Ls6 intake with injectors
Hooker headers
Muncie m-21 close ratio
Dino tune when done
Just a Friday night snotty street cruiser
Any suggestions would greatly be appreciated. Thanks
04-18-2015, 04:15 PM
#3
Teching In
Thread Starter
Join Date: Oct 2013
Location: Castle rock Colorado
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
3.31 gears in it!
I might go 3.55 with Posi, not sure yet on gears
04-18-2015, 04:42 PM
#4
One way to help a larger cam is to increase the compression ratio. Now you can wack the heads 030 or 040 but then you lose piston to valve clearance. Another way is to swap out the dished pistons for some good used 4.8 flat tops but once you release the rod bolts the big ends of the rods will most likely need a bit of machine shop attention. Even the factory bolts don't seem to re-torque perfectly round. A few licks on the rod hone machine to bring them back into spec works but something to keep in mind.
IIWY I'd leave the short alone, mill the factory heads about .025" and keep the camshaft a bit conservative since you're not running a lot of gear and that close ratio trans will help by not dropping the revs too much on gear changes. If you can afford it the neatest little head for your application would be the Trick Flow CNC 205. It flows extremely well has great velocity and with the powdered metal valve guides will work with the factory rocker arms. Also the 58 cc chambers will help get you to almost 10:1 compression which would be a decent match for an EPS 222/226 cam. Tick and Cam Motion also have similar sized sticks but that's about the range to look at with this smallish 325 inch air pump.
IIWY I'd leave the short alone, mill the factory heads about .025" and keep the camshaft a bit conservative since you're not running a lot of gear and that close ratio trans will help by not dropping the revs too much on gear changes. If you can afford it the neatest little head for your application would be the Trick Flow CNC 205. It flows extremely well has great velocity and with the powdered metal valve guides will work with the factory rocker arms. Also the 58 cc chambers will help get you to almost 10:1 compression which would be a decent match for an EPS 222/226 cam. Tick and Cam Motion also have similar sized sticks but that's about the range to look at with this smallish 325 inch air pump.
04-18-2015, 05:12 PM
#5
Teching In
Thread Starter
Join Date: Oct 2013
Location: Castle rock Colorado
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
One way to help a larger cam is to increase the compression ratio. Now you can wack the heads 030 or 040 but then you lose piston to valve clearance. Another way is to swap out the dished pistons for some good used 4.8 flat tops but once you release the rod bolts the big ends of the rods will most likely need a bit of machine shop attention. Even the factory bolts don't seem to re-torque perfectly round. A few licks on the rod hone machine to bring them back into spec works but something to keep in mind.
IIWY I'd leave the short alone, mill the factory heads about .025" and keep the camshaft a bit conservative since you're not running a lot of gear and that close ratio trans will help by not dropping the revs too much on gear changes. If you can afford it the neatest little head for your application would be the Trick Flow CNC 205. It flows extremely well has great velocity and with the powdered metal valve guides will work with the factory rocker arms. Also the 58 cc chambers will help get you to almost 10:1 compression which would be a decent match for an EPS 222/226 cam. Tick and Cam Motion also have similar sized sticks but that's about the range to look at with this smallish 325 inch air pump.
IIWY I'd leave the short alone, mill the factory heads about .025" and keep the camshaft a bit conservative since you're not running a lot of gear and that close ratio trans will help by not dropping the revs too much on gear changes. If you can afford it the neatest little head for your application would be the Trick Flow CNC 205. It flows extremely well has great velocity and with the powdered metal valve guides will work with the factory rocker arms. Also the 58 cc chambers will help get you to almost 10:1 compression which would be a decent match for an EPS 222/226 cam. Tick and Cam Motion also have similar sized sticks but that's about the range to look at with this smallish 325 inch air pump.
04-18-2015, 07:15 PM
#6
On The Tree
iTrader: (10)
Join Date: Jul 2008
Location: Lindale, TX
Posts: 151
Likes: 0
Received 0 Likes
on
0 Posts
I just finished an LS swap into a 70 GTO. 5.3 liter also. Mine had the flat top pistons. I went with PRC stage 2.5 heads milled to 58cc chambers and a Pat G spec EPS cam 222/224 .604/.604 112+1. No numbers yet as the tuning isn't done but It's a great combo with power everywhere and no loss in drivability.
04-19-2015, 08:37 AM
#7
Teching In
Thread Starter
Join Date: Oct 2013
Location: Castle rock Colorado
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
I just finished an LS swap into a 70 GTO. 5.3 liter also. Mine had the flat top pistons. I went with PRC stage 2.5 heads milled to 58cc chambers and a Pat G spec EPS cam 222/224 .604/.604 112+1. No numbers yet as the tuning isn't done but It's a great combo with power everywhere and no loss in drivability.
I looked into the prc stage 2.5 head setup and cam package. I was quoted $1,700.00, I figured I could find a decent 6.0 and stab a cam at it for that price!! I'm in this motor $0 it's just something I have laying around so I'm still insure what I want to do with it?!!
Trending Topics
04-20-2015, 04:55 PM
#8
Moderator
iTrader: (4)
Join Date: Jul 2014
Location: My own internal universe
Posts: 10,452
Received 1,852 Likes
on
1,152 Posts
Here's the deal - stock 5.3 heads suck. you can cam it all you want, but the heads will be your limiting factor. To give you an idea, I watched two tahoes race that were similarly equipped (2WD only). THe 5.3 had 706 heads, and the 4.8 had 243 heads. The 4.8 outran the 5.3. If you're on a budget, here is a decent option:
Grab a set of used 243 or 799 heads and mill them down just a touch to get a flat surface - around 62CC. Install a .041" head gasket to tighten up your quench a bit. If you are willing to play with springs, the EPS 222 suggested above is a good option. If you don't want to mess with springs, consider a drop in cam. You could also grab a LS2 or LS6 cam used pretty cheap. I have that LS6 cam in a truck and HATE it, but in a car with some decent gears, it might be a decent runner, and it would work with the stock 243 springs.
Don't fool yourself, it won't put 400 to the wheels or anything, but it would run nice and have more power than the old 400 small block and should be pretty efficient overall. Since you're going to buy heads anyway, why not buy good ones?
Grab a set of used 243 or 799 heads and mill them down just a touch to get a flat surface - around 62CC. Install a .041" head gasket to tighten up your quench a bit. If you are willing to play with springs, the EPS 222 suggested above is a good option. If you don't want to mess with springs, consider a drop in cam. You could also grab a LS2 or LS6 cam used pretty cheap. I have that LS6 cam in a truck and HATE it, but in a car with some decent gears, it might be a decent runner, and it would work with the stock 243 springs.
Don't fool yourself, it won't put 400 to the wheels or anything, but it would run nice and have more power than the old 400 small block and should be pretty efficient overall. Since you're going to buy heads anyway, why not buy good ones?
04-21-2015, 08:50 AM
#10
Moderator
iTrader: (4)
Join Date: Jul 2014
Location: My own internal universe
Posts: 10,452
Received 1,852 Likes
on
1,152 Posts
I assumed all 243 heads had the .550 lift springs. my bad
05-06-2015, 09:59 PM
#11
Teching In
Thread Starter
Join Date: Oct 2013
Location: Castle rock Colorado
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
Here's the deal - stock 5.3 heads suck. you can cam it all you want, but the heads will be your limiting factor. To give you an idea, I watched two tahoes race that were similarly equipped (2WD only). THe 5.3 had 706 heads, and the 4.8 had 243 heads. The 4.8 outran the 5.3. If you're on a budget, here is a decent option:
Grab a set of used 243 or 799 heads and mill them down just a touch to get a flat surface - around 62CC. Install a .041" head gasket to tighten up your quench a bit. If you are willing to play with springs, the EPS 222 suggested above is a good option. If you don't want to mess with springs, consider a drop in cam. You could also grab a LS2 or LS6 cam used pretty cheap. I have that LS6 cam in a truck and HATE it, but in a car with some decent gears, it might be a decent runner, and it would work with the stock 243 springs.
Don't fool yourself, it won't put 400 to the wheels or anything, but it would run nice and have more power than the old 400 small block and should be pretty efficient overall. Since you're going to buy heads anyway, why not buy good ones?
Grab a set of used 243 or 799 heads and mill them down just a touch to get a flat surface - around 62CC. Install a .041" head gasket to tighten up your quench a bit. If you are willing to play with springs, the EPS 222 suggested above is a good option. If you don't want to mess with springs, consider a drop in cam. You could also grab a LS2 or LS6 cam used pretty cheap. I have that LS6 cam in a truck and HATE it, but in a car with some decent gears, it might be a decent runner, and it would work with the stock 243 springs.
Don't fool yourself, it won't put 400 to the wheels or anything, but it would run nice and have more power than the old 400 small block and should be pretty efficient overall. Since you're going to buy heads anyway, why not buy good ones?