Putting in a ZZ502
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Pro
Joined: Jul 2009
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From: Gambrills Maryland
Putting in a ZZ502
I have a stock ish 1968 with 4 speed and 4.11 rear. I am thinking about installing a ZZ502 in it. What other mods do I need to the car to handle this engine. I am not racing the car...she is just for the street. Do I need to make any changes to the drive train or suspension to handle the extra weight, etc ???
Le Mans Master
Joined: May 2003
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From: Fernandina Beach FL
2023 Restomod of the Year finalist
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The ZZ502 w/ alum heads/intake is not that much heavier than a cast iron headed/ intake small block....I'm thinking about 50lbs.
If you had an A/C small block and dropping the it when you go to the 502 - even less of a difference.
Drivetrain- If you put sticky tires on it- you can break things ( small block as well)-otherwise you should be OK.
You'll also need to swap out the oil pan(truck pan it comes w/ is too low)- add an electric fuel pump and buy a mount for you clutch z-bar....
Richard
If you had an A/C small block and dropping the it when you go to the 502 - even less of a difference.
Drivetrain- If you put sticky tires on it- you can break things ( small block as well)-otherwise you should be OK.
You'll also need to swap out the oil pan(truck pan it comes w/ is too low)- add an electric fuel pump and buy a mount for you clutch z-bar....
Richard
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Also understand the ZZ502 is about out of steam by 5500 rpm...those 4.11s are going to have it up there pretty quick.
JIM
JIM
Race Director
Joined: Jun 2000
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From: FL
• Clutch linkage bosses (implies both bosses) are now drilled and
tapped. When using cast-iron exhaust manifolds,
lower head bolts may need to be replaced with
bolts with shorter heads for clearance
• 502 engines now have a mechanical fuel
pump boss!
Racer
Joined: Oct 2006
Posts: 435
Likes: 18
From: Florida
For the money, you would be well served talking to Vortecpro about a built engine. Mark (Vortecpro) builds a badass engine with GM iron heads, but will put whatever head you want on it, and for cheaper than a crate ZZ502. His engine will not be out of steam by 5500 either 
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Racer
Joined: Oct 2006
Posts: 435
Likes: 18
From: Florida
He has a website and there is a forum member with one of his engines, shouldntbehere is his screen name I think...
http://www.vortecproperformance.com/...binations.html
http://www.vortecproperformance.com/...binations.html
Le Mans Master
Joined: May 2003
Posts: 8,877
Likes: 3,556
From: Fernandina Beach FL
2023 Restomod of the Year finalist
2020 C3 of the Year Winner - Modified
Need the new oil pan and maybe a better cam but no need for an electric fuel pump or z-bar mount. Per the latest GM catalog:
• Clutch linkage bosses (implies both bosses) are now drilled and
tapped. When using cast-iron exhaust manifolds,
lower head bolts may need to be replaced with
bolts with shorter heads for clearance
• 502 engines now have a mechanical fuel
pump boss!
• Clutch linkage bosses (implies both bosses) are now drilled and
tapped. When using cast-iron exhaust manifolds,
lower head bolts may need to be replaced with
bolts with shorter heads for clearance
• 502 engines now have a mechanical fuel
pump boss!
The cam change is a good idea-but running the stock lifters I don't think you can go over .555 lift.....Then you have to change the lifters (NOT inexpensive ) and then the springs...
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
He has a website and there is a forum member with one of his engines, shouldntbehere is his screen name I think...
http://www.vortecproperformance.com/...binations.html
http://www.vortecproperformance.com/...binations.html
I think one of Mark's $5k, 570hp 468" would do the trick here....spank a 502 for less money and not burn a quart of oil every month...lol
Keep in mind Vortecpro engines are all iron heads so you may want to change front springs....(although I am still running my original SB with AC springs with 147k miles on them...but they are way soft.)
Burning Brakes
Joined: Dec 2003
Posts: 1,004
Likes: 7
From: Adelaide South Australia
A few GM ZZ502's crate engines have been installed locally, and they have been a disappointment to their owners. They have a hell of a lot of low down torque which results in lots of tyre smoke, but run out of puff too early in the revband.
I've spanked a few with my 383 sb. Just the combination of upper rpm power with good gearing (5sp TKO600, 3.73 diff) works well in a stout small block.
You've already got a 4.11 rear end. Unless you're running slicks, you'll never get the power down with that ZZ502 big block.
If you go to the trouble of fitting a big block, then aim for a target of over 600hp. Different cam/head combo. Sacrifice some low end grunt and shift torque higher in the rpm band make good power to 6500 rpm.
Motor will still be reliable and it will really make the effort of swapping out to a big block worthwhile.
You will of course, need to strengthen the entire driveline.
Do this, and you'll be grinning every time you sit behind the wheel.
I've spanked a few with my 383 sb. Just the combination of upper rpm power with good gearing (5sp TKO600, 3.73 diff) works well in a stout small block.
You've already got a 4.11 rear end. Unless you're running slicks, you'll never get the power down with that ZZ502 big block.
If you go to the trouble of fitting a big block, then aim for a target of over 600hp. Different cam/head combo. Sacrifice some low end grunt and shift torque higher in the rpm band make good power to 6500 rpm.
Motor will still be reliable and it will really make the effort of swapping out to a big block worthwhile.
You will of course, need to strengthen the entire driveline.
Do this, and you'll be grinning every time you sit behind the wheel.
