67 Roadster ZZ5/327-300 engine swap

[Alex A.]

Gentlemen,

This is my first post and I am hoping someone can clear up some concerns I have regarding an up coming engine swap. The plan is to remove and store the original 327/300 replacing it with an already purchased non-serpentine belt ZZ5. I have found lots of helpful info on this site but nothing specific to these questions. Clearly, I should have asked these questions "before" and not "after" purchasing the engine.

- l will be using either GM Performance Catalogue 670 or 770-cfm electric choke Holley. Will this combo, along with stock air cleaner, fit under the small block hood.

- Will the rather large looking ZZ5 harmonic balancer clear the front frame cross member ?

I would appreciate any and all comments or suggestions in regard to this engine swap.

Thank you.

[Patrick B.]

Re: 67 Roadster ZZ5/327-300 engine swap

This looks like a good swap. The cross member was designed for a 427 with an 8" balancer so it will certainly clear a 350 with an 8" balancer. The pictures of a ZZ5 show a manifold of similar height to an LT-1 which should clear the hood fine with the stock air cleaner.

[Alex A.]

Re: 67 Roadster ZZ5/327-300 engine swap

Hi Patrick,
Thank you for the quick reply. It was important to me that the swap did not change the vehicles stock appearance. I am sensitive to the fact that this site is dedicated to the preservation of originality and correct Corvette restoration. I went through a lot of trouble and expense by religiously following the NCRS restoration guide during the full restoration of my car but I need more power and modifying the numbers matching engine was not an option. I felt an engine swap was a lesser sin.
Alex

[Joe L.]

Re: 67 Roadster ZZ5/327-300 engine swap

Gentlemen,

This is my first post and I am hoping someone can clear up some concerns I have regarding an up coming engine swap. The plan is to remove and store the original 327/300 replacing it with an already purchased non-serpentine belt ZZ5. I have found lots of helpful info on this site but nothing specific to these questions. Clearly, I should have asked these questions "before" and not "after" purchasing the engine.

- l will be using either GM Performance Catalogue 670 or 770-cfm electric choke Holley. Will this combo, along with stock air cleaner, fit under the small block hood.

- Will the rather large looking ZZ5 harmonic balancer clear the front frame cross member ?

I would appreciate any and all comments or suggestions in regard to this engine swap.

Thank you.

Alex-------

I believe you will have one major problem. The ZZ5 is equipped with a long leg style waterpump. This style will not work well in a Corvette chassis. Among other issues, the crankshaft pulley used with it will be so far forward that there may well be interference. So, you may have to remove and replace the waterpump with a short leg type. Unfortunately, that means you'll also have to replace the complete pulley system. The crankshaft pulley used with the short leg waterpump and 8" balancer will fit your crossmember.

Otherwise, I agree with Patrick. I think the manifold height should fit without problems. However, if there were a height problem the most you would have to do is to swap out the intake manifold for something like an Edelbrock 2101. That manifold will fit and it will support either a Holley or Q-Jet carb.

One thing you need to check, though: make sure that your stock air cleaner will fit and seat properly on the Holley you have. If it doesn't, report that here and we'll offer you some options.

[Alex A.]

Re: 67 Roadster ZZ5/327-300 engine swap

Thanks Joe,

I will replace the water pump with a short leg and with the engine on a stand, install the alternator and all pulleys to make sure everything lines up. Air cleaner base to carburetor seating and stock air filter fit will be established at that time and reported.

I will deal with any hood clearance issues once the engine is in the car and report on any success or complications.

[Duke W.]

Re: 67 Roadster ZZ5/327-300 engine swap

Gentlemen,

Clearly, I should have asked these questions "before" and not "after" purchasing the engine.

Yeah, if it has a 657 block you can easily stroke it to 3.75", massage the heads, and install a McCagh Special camshaft retarded four degrees. It will maintain original appearance and idle behavior, but have substantially more torque and power from off idle to 6000 revs. No one would ever know unless you took them for a WOT ride through the gears, and even if your original engine was recently rebuilt, the cost would probably be less than the new engine and associated hardware, and you'd still have an original numbers matching engine and associated components that have no obvious modifications.

Duke

[Alex A.]

Re: 67 Roadster ZZ5/327-300 engine swap

Thanks Duke,
Thanks for taking the time to respond.
Too late now. The original engine was rebuilt and the ZZ5 has already been purchased and delivered. I was seduced by the ZZ5's 400hp power rating and GM provenance. It would have probably been wiser and a much less obvious swap to rebuild and install the 70 LT-1 engine who's parts I have been patiently assembling for the last few years, but the quote I got for a rebuild was more than a fully assembled ZZ5 and so I took the plunge.
Alex

[Joe L.]

Re: 67 Roadster ZZ5/327-300 engine swap

.......but the quote I got for a rebuild was more than a fully assembled ZZ5 and so I took the plunge.
Alex

Alex-------


Very often this is how it is. And, when everything is said-and-done with a rebuild you still have a lot of USED components.

[Greg H.]

I hope you find this information helpful. Because I am performing a complete restoration, my project may not be running until this time next year. Good Luck!

[Joe L.]

Re: 67 Roadster ZZ5/327-300 engine swap

Hi Alex.



My response to your request is based on my ZZ1 experience, I am not aware of all of the modifications to the ZZ series that have occurred since I bought a ZZ1 crate engine back in 1991. My current task is like yours, I am also working to adapt my new and complete 1991 - ZZ1 small block to my 67-air coupe.



So far, I have found the following differences when transferring my 67 C-2 parts on to the ZZ1 small block.



Intake Manifold – When I first got my ZZ1, I removed the aluminum intake manifold and installed it on my non-matching C2 small block daily driver. Now it has well over 85,000 miles without any interference. The ZZ1 intake will work with the original standard holly carb and factory air cleaner. For your reference, I have two part numbers for the ZZ1 intake – the service number is 10185024 and the number on the manifold is 14044836. I don’t know what will be standard on your ZZ 5. The manifold looks like the same physical size as the original L79 – 350hp. My most recent information source about your ZZ5 is an old 2013 catalog that illustrates the ZZ4 assembly only and I can see that the front oil filler boss that was standard on all of the old intakes and my ZZ1 manifold has been omitted on the ZZ4 and maybe on the 5. That is unfortunate because I was able to insert the traditional oil filler tube into my ZZ1 manifold so that the intake matches the early manifolds.


Oil Pan – The oil pan that was supplied on my ZZ1 was intended for a Z28, not a corvette application. My guess is that your ZZ5 oil pan will be the same. Also, the internal crank baffle is not included. My C2 has power steering and as you are aware, the power steering oil pan must be shorter to make room for the addition of the power steering ram, the power steering ram must live in the available space between the front edge of the oil pan and the relay rod so I had to find a later series oil pan that included the revised one piece rear main oil seal. After 1986, all GM small blocks have a one-piece rear main seal and the rear of all the small block oil pans were produced to work with that change. These corvette oil pans (C-4) were in production from 1986 until 1996 and now have been discontinued by GM. Finding a used power steering or standard oil pan is not difficult. If you need one, I know of an excellent source. The companion internal oil baffle and main bearing studs are still available through GM parts. Also, if you change your oil pan you will need to change your oil pump pick up tube. I got a Melling tube from a speed shop.



Pulley Alignment – easy to do with the engine out of the car and most every accessory will transfer.


Exhaust Manifolds – The original exhaust manifolds have vertical castings bits that contact / interfered with valve cover perimeter edges. I have installed after market header gaskets to move the castings away from the heads and I still had some interference so I cut four small notches; two on each bank into the valve cover edge flanges to gain the needed clearance. I hope the covers won’t leak.


Flywheel – you will need an exterior balanced flywheel – GM has a lot of options.


I have a complete series of photos that may help you, I am unable to post, blocked by the photo structure.


I hope you find this information helpful. Because I am performing a complete restoration, my project may not be running until this time next year. Good Luck!

Greg------

The GM #10185024 is no longer available in SERVICE and is not used on current ZZ-series engines. The current manifold is GM PART #10185063. It has no provisions or boss for an oil fill tube. However, it should fit under the hood of the C2. It can be used with either a Holley or Q-Jet carb.

The oil pan supplied with the ZZ-series engines is, indeed, not a Corvette configuration oil pan and is the style used on earlier Camaros. However, it should fit a Corvette chassis with no problems at all. It has a shorter, deeper sump than the standard 1963-74 Corvette oil pan. In fact, this same configuration pan was used on 1975-79 Corvettes and those cars have the same chassis configuration as 1963-74. It will also work just fine with power steering (as it did for 1975-79). No external (i.e. engine mounted) baffle was ever used with 1963-67 "5 quart" Corvette oil pans or is used with the oil pan installed on ZZ-series engines.

12.75", standard weight, externally balanced (i.e. for engines with 1 piece rear seal) flywheel is GM #14088650.

[Greg H.]

Re: 67 Roadster ZZ5/327-300 engine swap

Hi Joe,

Thanks for your insight into the baffle application. Do you recommend that I remove it? Easy to do with the engine still on it's stand.

[Joe L.]

Re: 67 Roadster ZZ5/327-300 engine swap

Hi Joe,

Thanks for your insight into the baffle application. Do you recommend that I remove it? Easy to do with the engine still on it's stand.

Greg-------


I was not aware that the ZZ5 engine was equipped with a baffle. However, "the proof is in the pudding". If it has an external baffle (i.e. block mounted with main cap studs), I'd definitely leave it in place. If you have the pan off already, I'd like to see a photo of this baffle.

[Alex A.]

Re: 67 Roadster ZZ5/327-300 engine swap

Thanks Guy's,
I certainly appreciate all the dialogue. I find it very helpful as some of the concerns raised in this thread had not even been considered.
Nothing is ever as simple as it first appears and my intent when undertaking this project was not to wreck all the work that went into the just completed restoration of my car.
My car is a 67 Roadster, 327ci /300hp, 3:36 diff., M-20 4 speed, factory side pipes.
This is what I have purchased to date:
ZZ5 Base engine, GM short nose aluminium water pump , GM Street Performance fuel pump, GM High-Torque mini starter, Holley 670 CFM carburetor with electric choke (I'm conflicted on whether or not I should exchange it for the 770 cfm version of the 4150 style. No real guidance anywhere). I have also purchased a MSD Corvette Mechanical Tach-Drive Distributor with vacuum advance, MSD Street Drive ignition box, coil and plug wires. GM flywheel pressure plate and clutch to match original. Headers have not yet been purchased but I have read somewhere that McJacks has ceramic coated shorty's with alternator mount provision that will work. Have yet to purchase but have earmarked an aluminium rad with twin fans.
As I mentioned earlier, the entire and complete original motor, front to back, along with original rad and shroud are to be retired and stored to be reinstalled at some later date.
That's it so far.

[Joe L.]

Re: 67 Roadster ZZ5/327-300 engine swap

Thanks Guy's,
I certainly appreciate all the dialogue. I find it very helpful as some of the concerns raised in this thread had not even been considered.
Nothing is ever as simple as it first appears and my intent when undertaking this project was not to wreck all the work that went into the just completed restoration of my car.
My car is a 67 Roadster, 327ci /300hp, 3:36 diff., M-20 4 speed, factory side pipes.
This is what I have purchased to date:
ZZ5 Base engine, GM short nose aluminium water pump , GM Street Performance fuel pump, GM High-Torque mini starter, Holley 670 CFM carburetor with electric choke (I'm conflicted on whether or not I should exchange it for the 770 cfm version of the 4150 style. No real guidance anywhere). I have also purchased a MSD Corvette Mechanical Tach-Drive Distributor with vacuum advance, MSD Street Drive ignition box, coil and plug wires. GM flywheel pressure plate and clutch to match original. Headers have not yet been purchased but I have read somewhere that McJacks has ceramic coated shorty's with alternator mount provision that will work. Have yet to purchase but have earmarked an aluminium rad with twin fans.
As I mentioned earlier, the entire and complete original motor, front to back, along with original rad and shroud are to be retired and stored to be reinstalled at some later date.
That's it so far.

Alex-------



The 675 CFM carb you have will be just fine for this application and just fine for street use. If you over-carb, you lose some driveability. If you under-carb (and I don't mean to imply that the 675 CFM carb will amount to under-carbing) all you lose is some high RPM power that you're never going to use on the street anyway. The primary advantage of the 4150 carb in your application is that it uses a secondary metering block instead of a secondary metering plate. For your application, that's probably inconsequential.

I don't like headers on a street car and would never personally use them. But, use them if you must. When you've had your fill of them, you'll go back to cast iron manifolds.

[Alex A.]

Re: 67 Roadster ZZ5/327-300 engine swap

Thanks Joe,
I'll take your advice and stay with the 675 CFM. Makes sense.
As far as the headers are concerned, I was led to believe that the ZZ5 exhaust ports didn't quite line up with the openings on the stock cast iron manifolds otherwise I have no problem using them.
I'll look into the port alignment issue to see if port misalignment is consequential.