irelandr

OK just some quick questions, I searched and did not find much on early C3 swaps with a ZZ6. Interested in 70-72 C3's mainly.

What is required to put one in other than drop it in and bolt it up. What are the little things you need to take care of?

Will it fit with a 700R4 automatic, what else does that need if it is already installed and running with stock 350.

Will the factory hood clear (non LT-1 or big block hood)

What am I missing or not thinking about?

Thanks

Raphiki

It's a standard 350 block so it should be an easy install. There are lots of posts on ZZ4 installs which are externally identical.

irelandr

Anyone? I found 1 or 2 other people asks and same answer it will fit, I think we knew that but thought we would find someone that is or has done it that has some hints or tips, part numbers, what to change or leave alone.

I think I have read almost every ZZ4 post and they are helpful but was hoping for a little more detail, a lot are later 70's and 80's. There used to be one with parts needed, and all the steps but can't find it now. Some are from early 2000's, maybe there are other ways to do it now that more people are doing the swap.

A hemi will fit if I want it to but I would need lots of details on how so was hoping someone was doing one now or has done one on a car in the same year group as mine.

Things I am thinking might be issues, if I had the turn key will the serpentine set up it comes with clear the frame (harmonic balancer) and A frames, steering, etc. Borgson steering?

With the manifold will I be able to close my hood or do I need a LT1/BB hood or L86 hood?

Has anyone did it with a 700R4 already in the car?

Is it a reverse water pump? Will the stock one bolt right on or do I need a certain year water pump. I know people said you have to grind off one bolt on the timing cover but has anyone used the long water pump and electric fans, what else needed done?

Whats with the fuel [ump, most said stock will bolt right on, at least one said they needed to do machine work to use it? Isn't there a rod that goes in also to work the stock fuel pump?

I have HEI so the wiring is already taken care of so no need to remove the resistor wire and I have a mini starter so that is set up what am I missing?

I know details right..... the big things are easy but the devil is in the details.

Sigforty

See this and let me know if you have questions.

http://www.boomnit.com/Cars/Project71/Engineswap.html

redcruz1120

I put a ZZ5 in my 74 last year. I don't see much difference if any from the year models you mention. I bought a turnkey engine and it also came with a reverse flow water pump and didn't grind that famous bolthead on the timing chain cover. I did have to flip the Idler pulley upside down on the GM serpentine system so it wouldnt hit the passenger side A arm.The only major issue I had was the temperature sending unit that goes in the drivers side head. I had it machined down to fit the 3/8" port as I did not want it on the thermostat housing. On the cooling side I used a Dewitts radiator with electric fans. I also kept my 400TH Transmission with a 2500 Stall for now. I do have a higher hood so I wouldnt know if it would clear the original rise... I hope that helps.

rcread

Your questions indicate to me you should not be doing this yourself. It involves taking one small block and putting another one in. Maybe you should just farm this job out.

irelandr

Thanks, every little bit helps.

irelandr

Thank you, that does help, still a few questions so hopefully others will know.

irelandr

It is people like you that turn off new people coming to a place that offers help and hope with your snide remarks. I had someone tell me not long ago he did not bother with Corvette groups because the people were stuck up and thought they were better than every one else and you are a perfect example.

You question my abilities and have no clue what they even are and offer no help or value at all.

The small block has several decades of different cars it came in, the ZZ series came in none so it might have to be tweaked some to fit, or there might be easier ways to do something I did not think about, especially in an early C3 with factory low hood and a 700R4 transmission that did not come in early C3's.

Am I qualified, I worked for 5 years as a mechanic in and out of high school, and 15 years active duty in the air force, attended multiple training courses on transmissions, engines and AC in the Air Force and every GM factory course at a GM training center in Oklahoma city in the late 70's including a week just doing quadrajets and another doing automatic transmissions. I also have a college degree in Automotive Mechanics. That's 16 years as a primary job until the Air Force thought I would do great in computers and I now work computers.

I think I am qualified to change an engine but feel my questions are valid and people who want to help (unlike you) know will the hood fit, or did they change carburetor, or will the front end that you can get on the ZZ5 fit and clear A-Arms and other thing like that.

And as you said, your answers indicate to me you are rude arrogant and not here to help and perhaps should take you opinion with you and let this forum be what if can be without trying to show up people or act like you know it all.

If you are not here to help fellow Corvette fans what are you here for??

rcread

You could have just said "I'm a mechanic". Saves a lot of typing and I would have said "Oh, cool."

Seriously, though, I would just jump in. There is nothing that will come up that you can't handle.

irelandr

In the end i probably will just jump in however sometimes its good to get all the info you can and compare it, might decide to go a completly different way even based on it, or get a bigger hammer.

rcread

By bigger hammer, do you mean big block? I don't think you'd regret that move.

redcruz1120

If you decide to do it, feel free to pm or post questions. The biggest issue I thought I was going to have was the clearance between the frame and front lower pulley.As you can see it cleared with plenty of room. The first picture is the belt the motor package came with and the second picture is a second belt larger by 1 inch due to flipping the idler pulley.

irelandr

You never know it could happen, I also thought of the RamJet 350, or 383. Not going to race it but hate to be the last one to arrive! When I bought the 700 transmission I changed out my 3.08 differential for a 3.36 both built for lots of HP/Torque so can go from what I have now (base engine) up to almost anything room and allowance will allow.

irelandr

That looks great. Thanks for the offer. I know I can get an edelbrock water pump that will fit without filing off the bolt if I stay with stock pulley system. My concerns were the pulley since it is bigger so you helped there and other than that since it comes with an automatic flex plate is will it fit with the 700R4 transmission (same flywheel as my TH400 had, with all the weights solid and not moving all over). The big one is the hood clearance because on the 68-72 I think they have the least hood clearance of all the C3's. If I can stay with the sleeper hood thats better, no cost and no clue to others whats under it. I have DeWitts radiator and electric fans and Vintage Aire system replacing stock AC so lots of room on that side. Also have borgson steering box but that would only affect header clearance on some headers or engines.

I see the difference in the belt i the second picture with the deflection towards the engine, makes the statement to insallt it upside down make more sense now.

Thanks again.

Kidster71

Hello Irellandr,
I am looking to do a similar swap, 1971 coupe, 700R4 trans, dewitts duel fan rad, classic auto air AC, rack and pinion steering and want to drop in a ZZ6 EFI (EFI is one inch lower on the air cleaner), I was wondering how it all went for you?
Specifically I am wondering about what D headers did you use?
Did you reconnect the steering column lock cable to the 700R4?
Does the stock throttle cable fit?
and more...

Thank you,
Kidster

69_Shark

OP:
A TH350 transmission may require you to shorten your drive line.

Scott

Kidster71

Thank you Scott

There is a lot of info on the drive line cuz its the same for a lot of other chevys so I did actually have that list of needed changes
My 71 actually has a TH400 so the yoke has to change down to 27 spline as well as the drive shaft shortening. I have a great local shop for that one.

Cheers,
Richard

derekderek

there is also no law sez you have to run the late model belts-water pump, etc setup. you could use all the orig stuff on the front of the engine. biggest diff is the flywheel or starter wheel. and that is just buy it from summit. you could also get the zz6 heads and aftermarket roller lifters and cam. especially if current engine is in good shape.

irelandr

No not yet life and building a new house kind of got in the way but I did get a lift in he deal so not bad. Finishing th ebasement now and then will be able to get to things again and plan on it. Still worried about hood clearance since I have the stock small block hood but the EFI sounds interesting, any part number or info in it.

I did not reconnect the steering lock but wired it in place so it does not lock while driving.

Let me know how it goes, I am still looking to go there.