autolover3
Full Access Member
Well my 99 has been going under a few modifications both performance and visual lately so once I get all my pictures organized I'm going to be ******* them out soon! 
This will be thread on the performance side of things. To start I have a 99 Yukon with 5.7, 4l60e, 3.73s. So far here's whats been done:
-Blackbear Tune, light transmission increase, 91 octane
-Pacesetter longtubes, egr, cat, muffler delete, with 3" duals into single 2.5" single exit
-Modified intake with Napa filter
-Thottle body blade mod
-Transgo HD2 shift kit with vette servo
-fresh t case rebuild with MA pump upgrade
Now that I'm in engines class I'm going internal.
-ZZ4 crate engine camshaft (208/221 dur. 474/510 lift 112 lsa)
-Comp Cams 918 beehive springs 787 retainers
-Comp Cams roller tipped rockers, (1.6 intake/1.52 exhaust ratios)
-New Manley valves (1.94" int/ bigger 1.6" exh)
-Singler roller Cloyes timing chain & sprockets
-Upgraded MFI assembly
~possibly jantzer ported TB
These are the pics I have so far of progress. I will be updating this until complete and with a review of the performance! Hopefully you guys enjoy this as much as me haha. Will answer any questions to the best of my knowledge and any input is greatly appreciated.
Here's some of my thoughts. ZZ4 cam should work well and is within capabilities of stock torque converter. Other options I threw around were the HT383 cam and LT4 hot cam, The zz4 is in the middle of those. More of a lower torque solid midrange power but not as much as top end as hot cam. Also should have a smooth idle ( as much as i love choppy lope i want it to sound stock) and no reduction of vacuum, ZZ4 has a wider lobe separation than stock cam and am hoping for a well mannered cruising daily driver that will have power when wanted.
With my choice of different ratio rockers... the cam duration is a 208/221 and .474/.510 lift. 1.6 intake will bring it to a more even .505/.510 and I think this should work well with the great flowing vortecs intake side. The 1.6" exhaust valves and lontube headers will help the flow on the exhaust and the long 221 duration and .510 lift IMO will work nice together on the 1.52 ratio. I am in no way a expert at this stuff yet but I am learning, hence why I am going to college and not just going to work in the oil field like all my friends here
Here is the start of the process.
Intake off
Manifold has some varnish, and ports are carboned up pretty good.
Cylinder Heads off
Instructor was impressed how good of shaped cylinders and pistons are in, guess I lucked out haha. Also this was my grandparents vehicle before me so I know for a fact it was never rodded on, except when I was younger my grandma did a wicked launch on a gravel road to show me that she could have fun haha!
manifold assembly will get cleaned up
Heads disassembled and beadblasted chambers, all was checked for cracks, none were found. Mine are the 062 castings.
Beadblasted rest of heads to clean them up. One head had some warpage, about .005". Also exhaust valves were getting worn that's why I went with 1.6" valves and insert seats Intake valves looked good just the margin was gettin too slim for my liking. Heads were sent to machine shop to get flat milled .010" for flatness and help raise compression slightly.
yep...
Was gonna replace oil pan gasket and since I was this far I thought it'd just be easier to remove block for cam removal/install. Also will be able to check necessary measurements and clearances for heads and what not with engine out.
Here is the new shiny ZZ4 cam next to stock one
Got lower manifold all cleaned up!
Valve covers and pan will be blasted and painted fresh black
New comp cams roller tipped rockers, IMO the classic logo looks badass
Removed old block heater, will be putting new one in for insurance
Got some screw in rocker arm studs too.
Got heads back from machine shop!
Like said before, milled .010", new exhaust seats for 1.6 valves, also will be installing the screw in studs so stud bosses will need to be ground down a few hundred thousandths, valve guides will be cut for retainer to seal clearance too.
Size compare new 1.6" valves to old 1.5"
New seats
Researched a little and am doing just a slight bowl blend and smoothing ports. Sorry I dont know how to draw on pics to show what I'm doing, hopefully you'll see. Heres before...
and after
and heres intake side
Just going by my eye and feeling every port and comparing to each other I'm just grinding down the ridges and high spots.
Also ground down rough sharp edges on lower manifold.
Also "deburred" or smoothed the edges of combustion chamber from the milling process
Whole lotta shiny
old left, new right (exhaust)
old right, new left (intake)
Cam going in along with new Cloyes roller chain and 3 keyway adjustable.
I first set timing with 4 degrees advanced, I've searched all over and people like to advance these apparently. The cam didn't come with a cam card or anything so I did some searching deep down and found some specs to go off of. Also instructor has been a great deal of help.
I degree'd my cam and found intake centerline at 104 degrees, which means the cam has 4 degrees advance ground into it. So I reinstalled the components straight up. Degree'd it again and got a 108 int centerline, and 116 exh centerline.
Also when degreeing a roller cam, use roller lifters haha. Woops
Got these beadblasted
Disassembled all the lifters and soaked them in carb cleaner, rinsed em off, cleaned with solvent and than brake cleaner, and blew em off with air. Inspected each and everyone. Normally one would just replace these but this is a "budget" build. Instructor also said with his experience the GM performance lifters are better than aftermarket such as Comp.
Found this makes for easy installation of the lock spring or whatever it's called
All back together
This will be thread on the performance side of things. To start I have a 99 Yukon with 5.7, 4l60e, 3.73s. So far here's whats been done:
-Blackbear Tune, light transmission increase, 91 octane
-Pacesetter longtubes, egr, cat, muffler delete, with 3" duals into single 2.5" single exit
-Modified intake with Napa filter
-Thottle body blade mod
-Transgo HD2 shift kit with vette servo
-fresh t case rebuild with MA pump upgrade
Now that I'm in engines class I'm going internal.
-ZZ4 crate engine camshaft (208/221 dur. 474/510 lift 112 lsa)
-Comp Cams 918 beehive springs 787 retainers
-Comp Cams roller tipped rockers, (1.6 intake/1.52 exhaust ratios)
-New Manley valves (1.94" int/ bigger 1.6" exh)
-Singler roller Cloyes timing chain & sprockets
-Upgraded MFI assembly
~possibly jantzer ported TB
These are the pics I have so far of progress. I will be updating this until complete and with a review of the performance! Hopefully you guys enjoy this as much as me haha. Will answer any questions to the best of my knowledge and any input is greatly appreciated.
Here's some of my thoughts. ZZ4 cam should work well and is within capabilities of stock torque converter. Other options I threw around were the HT383 cam and LT4 hot cam, The zz4 is in the middle of those. More of a lower torque solid midrange power but not as much as top end as hot cam. Also should have a smooth idle ( as much as i love choppy lope i want it to sound stock) and no reduction of vacuum, ZZ4 has a wider lobe separation than stock cam and am hoping for a well mannered cruising daily driver that will have power when wanted.
With my choice of different ratio rockers... the cam duration is a 208/221 and .474/.510 lift. 1.6 intake will bring it to a more even .505/.510 and I think this should work well with the great flowing vortecs intake side. The 1.6" exhaust valves and lontube headers will help the flow on the exhaust and the long 221 duration and .510 lift IMO will work nice together on the 1.52 ratio. I am in no way a expert at this stuff yet but I am learning, hence why I am going to college and not just going to work in the oil field like all my friends here
Here is the start of the process.
Intake off
Manifold has some varnish, and ports are carboned up pretty good.
Cylinder Heads off
Instructor was impressed how good of shaped cylinders and pistons are in, guess I lucked out haha. Also this was my grandparents vehicle before me so I know for a fact it was never rodded on, except when I was younger my grandma did a wicked launch on a gravel road to show me that she could have fun haha!
manifold assembly will get cleaned up
Heads disassembled and beadblasted chambers, all was checked for cracks, none were found. Mine are the 062 castings.
Beadblasted rest of heads to clean them up. One head had some warpage, about .005". Also exhaust valves were getting worn that's why I went with 1.6" valves and insert seats Intake valves looked good just the margin was gettin too slim for my liking. Heads were sent to machine shop to get flat milled .010" for flatness and help raise compression slightly.
yep...
Was gonna replace oil pan gasket and since I was this far I thought it'd just be easier to remove block for cam removal/install. Also will be able to check necessary measurements and clearances for heads and what not with engine out.
Here is the new shiny ZZ4 cam next to stock one
Got lower manifold all cleaned up!
Valve covers and pan will be blasted and painted fresh black
New comp cams roller tipped rockers, IMO the classic logo looks badass
Removed old block heater, will be putting new one in for insurance
Got some screw in rocker arm studs too.
Got heads back from machine shop!
Like said before, milled .010", new exhaust seats for 1.6 valves, also will be installing the screw in studs so stud bosses will need to be ground down a few hundred thousandths, valve guides will be cut for retainer to seal clearance too.
Size compare new 1.6" valves to old 1.5"
New seats
Researched a little and am doing just a slight bowl blend and smoothing ports. Sorry I dont know how to draw on pics to show what I'm doing, hopefully you'll see. Heres before...
and after
and heres intake side
Just going by my eye and feeling every port and comparing to each other I'm just grinding down the ridges and high spots.
Also ground down rough sharp edges on lower manifold.
Also "deburred" or smoothed the edges of combustion chamber from the milling process
Whole lotta shiny
old left, new right (exhaust)
old right, new left (intake)
Cam going in along with new Cloyes roller chain and 3 keyway adjustable.
I first set timing with 4 degrees advanced, I've searched all over and people like to advance these apparently. The cam didn't come with a cam card or anything so I did some searching deep down and found some specs to go off of. Also instructor has been a great deal of help.
I degree'd my cam and found intake centerline at 104 degrees, which means the cam has 4 degrees advance ground into it. So I reinstalled the components straight up. Degree'd it again and got a 108 int centerline, and 116 exh centerline.
Also when degreeing a roller cam, use roller lifters haha. Woops
Got these beadblasted
Disassembled all the lifters and soaked them in carb cleaner, rinsed em off, cleaned with solvent and than brake cleaner, and blew em off with air. Inspected each and everyone. Normally one would just replace these but this is a "budget" build. Instructor also said with his experience the GM performance lifters are better than aftermarket such as Comp.
Found this makes for easy installation of the lock spring or whatever it's called
All back together
