ZZ4

[Greg Hansen]

I am considering replacing my stock 69 350 that is in need of a rebuild with a ZZ4 and have several questions.
First will the manifold that comes with the ZZ4 fit under the stock hood?

Second can a stock short waterpump be used with the ZZ4 as it comes with a long waterpump?

Third will I need a carb with electric choke or will the original choke style work with the new manifold?

Are there any other problems with the installation that I have not thought of?
I am unable to access the archives at the present time, I keep getting an error message.

Thanks for any replys and comments.

[Jim T.]

Re: ZZ4

Greg I have a ZZ1 engine in my 70 and this earlier crate engine has a higher LT-1 styly intake and it just fits under my original hood. I am using a electric choke, can't remember right now at work if I could of used the heat activated choke system. The water pump on your 73 will work on the ZZ4. Is your 69 auto or 4-speed?

[Joe L.]

Re: ZZ4

Greg-----

The ZZ4 small block crate engine utilizes intake manifold GM #10185063. This manifold has provisions for both a hot air choke and EGR. You won't require the EGR provisions, of course. Although this manifold has hot air choke provisions, the 1969-style choke will not work with it. You will need to obatin the later style choke. I think that your best bet would be to obtain this piece as manufactured by Edelbrock. It's the same set-up as used on Performer intake manifolds.

The GM #10185063 is a medium riser, dual plane manifold. There should be no fitment problem with a 68-72 small block hood.

Installing a short leg-style waterpump is no problem, at all. Simply remove the long leg-style pump installed on the engine and bolt on the short leg-stlye. For a 1969, you require the 55-70 style short leg pump and NOT the 71-82 Corvette short leg pump. A brand new one is available under GM #12307815 or Delco # 251-166. This pump will have an unused external bypass fitting on the top of the pump which is plugged with the pipe plug supplied with the waterpump.

If you want a more original configuration waterpump, then you'll have to go rebuilt and find one with the GM #3782608 casting. That casting could have originally resided on a 1961 283, but it will bolt right up to a 2005 ZZ4 and work perfectly.

[Greg Hansen]

Re: ZZ4

I have a 3.70 posi rear, and a 700R4 from Bowtie Overdrives.

[Jim T.]

Re: ZZ4

Greg you are going to have a strong performer with this combination and the ZZ4. Excuse the previous error of mentioning 73 in my previous post. I used the water pump I took off my 70 on my ZZ crate engine instllation even though it was used and it is still in use. The reason I asked about your transmission concerns the flex plate that comes on the ZZ4 and previous crate engines. My 70's turbo 400 torque converter would not bolt to the the ZZ's supplied flex plate and I bought the larger correct one. The original flex plate will not work on the one piece rear seal cranks. I don't know the size of your current in use flex plate in your 69 with the 700R4. Quick and easy way is what starter nose are you using? If your current starter is a staggered bolt pattern you have the larger flex plate in use with your 700R4 and will need the larger flex plate. If it is the straight line bolt pattern you should be able to use the supplied flex plate on the ZZ4 and the torque converter of your 700R4 should bolt up. The smaller flex plate requires the use of the straight line bolt pattern starter nose.
Are you going to use your original exhaust manifolds?

[Jim Callan]

Re: ZZ4

Joe,,

Sorry to "hijack" this post but reading your response prompts me to ask - what is the difference between the 55-70 short leg w/pump and the 71-82 short leg w/pump ? What is the GM/Delco part# for a '71 w/pump ?

Thanks

Jim Callan

[Joe L.]

Re: ZZ4

Jim-----

The 55-70 style short leg waterpump was used on all 1955-68 passenger cars with SB engines as well as all 1955-70 Corvettes with small block engines. It has a 1-3/4" bolt circle hub (or, a dual pattern hub in the case of some PRODUCTION and most GM SERVICE and rebuilt waterpumps). It also has a 5/8" OD pilot shaft and a 5-9/16" or 5-11/16" hub spacing (i.e. the measurement from the base of the leg to the face of the flange). These pumps were manufactured in several different castings over the years and most are interchangeable. The primary difference in the castings relates to the presence or absence of the fitting on the top of the pump for external bypass. A pump with provisions for external bypass can be used for any SB application, with the bypass fitting plugged if necessary. The pumps without provisions for external bypass cannot be used for applications requiring external bypass. That is the primary exception to the "rule" of 55-70 small block short pump interchangeability.

The 71-82 Corvette small block pumps use completely different castings. These are designed for a larger bearing size. These pumps have a 3/4" pilot and have a 2-1/8" bolt circle (or, dual bolt circles, in some cases). No PRODUCTION application of these pumps ever used a 1-3/4" bolt circle, but, for some reason, these are sometimes found on these pumps, most likely the work of rebuilders.

The 71-82 Corvette pump had a hub spacing of ABOUT 5-3/4" (I don't have the exact spec handy, at the moment). The 71-E72 versions do not have provisions for external bypass (casting GM #3991399). The L1972 through 1982 versions do have provisions for external bypass which is not used for Corvette applications (GM casting #330813). It's also one of the very few cases in which an unused and prominent fitting was actually plugged with a square head pipe plug in PRODUCTION. All L72-82 Corvettes originally used the 330813 casting with the plugged bypass.

The 71-82 pumps had only 2 applications: 71-82 Corvette and some 72+ MD/HD truck applications. The truck applications are the reason that the external bypass casting came into use. Departing from normal practice, I guess GM figured that this was such a low volume waterpump application that they weren't going to continue manufacturing 2 different castings differing only by the external bypass. So, the plugged version was used for Corvette. Also, the above referenced pumps are the only small block ones that I know of in the whole Chevrolet "stable" that used a 3/4" pilot through 1982. The 71-74 big block pumps for Corvette and some MD/HD truck applications used the 3/4" pilot, though.

A 71-82 waterpump can be used on earlier small blocks. However, when this is done, the waterpump pullies, fan clutch, fan, and, sometimes, other pullies have to be changed, too.

The current GM part number for the 71-82 Corvette waterpump is GM #12458924. This pump will have a casting configured like the 330813 (i.e. with external bypass), but it likely won't carry the 330813 casting number.

[Jim Callan]

Re: ZZ4

Thanks Joe,

I'm in the process of rebuilding my '71 sb and thought I would put a new water pump on. The old one "seems" ok, but after sitting for 10 years I don't really trust it.

Jim Callan

[Joe L.]

Re: ZZ4

Jim-----

If it's a GM #3991399 casting I'd definitely have it rebuilt. It's likley the original waterpump and, even if it's not, it is an original configuration waterpump for your car. If it's a GM #330813, it's not original (a check of the dates on the pump will confirm that, too). In that case, if you go down and purchase a rebuilt waterpump for your car, you'll likely get another 330813 casting (unless they hand you a rebuilt "generic" casting pump).

Otherwise, save the pump if original and use the GM pump I mentioned as a new replacement pump.

[Greg Hansen]

Re: ZZ4

I will not be using my original manifolds. I am leaning towards Sanderson block hugger headers, but am considering 2 1/2" reproduction manifolds from a C2 year

[Jim T.]

Re: ZZ4

I had a pair of the 2 1/2 inch original 63 exhaust manifolds that I thought I was going to use and decided not to so I could use the 70's original air conditioning and alternator brackets. I continued the use of the 2 1/2 exhaust pipes that connect to the 2 inch original manifolds. Reason I asked about the exhaust manifolds you would use is that mine had a very slight exhaust leak on the passenger side. I bought the exhaust manifold gaskets used on C4 Corvettes and used them on both sides. This also isolated the cast iron manifolds from the aluminum heads. The original exhaust manifolds will not be a perfect match for the ZZ crate engines alumimun D port exhaust outlet design. The performance loss for my use of the engine is not a factor I am concerned with.