I plan on going with either 3100 or 3400 heads, depends on how cheap/what condition i can get ahold of. What I cant seem to find an answer on after searching thru a ton of posts on multiple sites are

1. Can I use the pushrods from a 3100 early 90s Cavalier?

2. Do I have to use the gaskets that match the pistons I go with? Like if i get 3400 pistons, I use 3400 head gaskets, not 3.4 gaskets right?

3. What throttle cable and bracketry do I use?

Im sure Ill have more, but thats all I got for now.

 

No, they will need to be measured, and ordered for your application

If you use 3400 pistons, you will need to use the 3400 gaskets, due to the pistons coming proud of the block, and quench hight is the issue here.

It would probably be easiest to use a 3100 FWD car cable, I want to say Buick of some sort, that is not coming to me now. I used this in my Datsun on an inline 6 cylinder engine with plenty of cable left over.

 

BTW, is $220 really an accurate price for a 3400 head gasket kit??!!!!

Would it be a good idea to get severe duty head gaskets or will the regular gaskets be sufficient?

 

above 2000 3100 and 3400 heads are the same. I had cavalier pushrods on mine while the cam was being fixed and I took it to 6500rpm with no problem, but they are too long for the right preload. I have felpro 2.8 gaskets on my 3.4/3400 that are .052" compressed, you don't need 3.4 gaskets. The cables and brackets are tricky. I had to trim the tv cable end and make my own bracket to keep the th700. You don't need to make one if it's a 4l60E or manual. You can use a throttle cable from an early 90's cavalier I believe. I Put my own together so I could adjust the firewall bracket to pedal length properly. The 3x00 bracket works.

 

So, one says 3400 head gaskets, another says theyre not needed. Hmmmmm.
Custom pushrods would be ideal, but I can get by safely with 3100 pushrods?

 

Trust me on the head gaskets, I've built and helped build several 3x00s and hybrids. The 3400 pistons come proud of the block by about .020", when coupled with the .060 compressed thickness of the head gasket that leaves a .040 quench hight, which you don't want to go smaller than, since at higher RPM, your pistons and heads will likely meet, with not so pleasant results.

The gen3 pushrods are way to short to use with the flat tappet cam.

Assemble the engine, get a push rod checker (probably need two, due to the differing lengths), measure and order the proper length.

One of my hybrids I used stamped rockers and gen2 pushrods on, and while it worked, I knew it was not ideal. If I was to build a hybrid again, I would just order the proper pushrods to have proper geometry. I know this hurt me in the long run.

I have some gen3 660 parts, let me know if you are looking for any parts.

 

Is .040 quench enough or can I get a thicker head gasket? That may be the "severe duty" gaskets I had mentioned. Ill have to check on the specs of the gaskets. They were through Fel-pro.

 

Well somehow mine's fine while shifting at 7k. According to my measurements the deck height is .0045".

 

One question: Why is it that a lot of people are doing or have done the hybrid swap but the answer to the pushrod question is always the same "Get a pushrod length checker and measure"? Doesn't anyone write this stuff down so others can use it? Even for a baseline with XX cam?

And we're all forgetting the early "bastard" years of the 3100... 94 and 95, where the 3100 had the non-roller cam, pushrod guides, and stamped rockers. I'll be using a set of those when my engine gets put back together.

What I want to know is what plugs to use...

 

Because we assume you'll be using newer heads with roller rockers. I didn't have problems with gen2 pushrods in my motor with roller rockers, but they were too long. Does that mean you won't have problems? Maybe. With an adjustable valvetrain (stamped rockers with studs) this isn't a problem.

 

If I can find the cash with the rest that's going on, I'm planning on a set of full roller rockers with poly locks for the adjustable setup... Already have the studs from the old heads installed (just need to nab some pushrod guide plates now ).

 

ALL gen3s have roller cams. Even the early 3100s that have stamped rockers.

It seems that no two people use the same cam, decking on the head, lifters, etc. The lengths vary little bit when something, even small is changed.

Just because you may be using "adjustable" rocker studs doesn't mean you'll have proper geometry. I had "adjustable" studs in my hybrid, using stamper rockers with gen2 pushrods, and KNOW 100% that the pushrods were not the correct length. The lash pattern was a bit off.

Adjustable rockers does NOT make up for incorrect length pushrods.

.040" quench hight is factory. I've ran tighter without issue, but I know it was only a matter of time before something got too close to something else.

 

:edit: Okay, scratch that. But, do tell me how the pushrods I got from a 1995 3100 are longer than the ones from the 1998 head set? Unless the guy I bought them from had the year wrong AND it was actually a Cavalier engine (IIRC, it was a Grand Am)...

 

It's been a long time since I dealt with the early 3100 stuff, but I believe the pushrods were slightly longer on the '93 to '95 3100, than the later one, due to difference of the stamped rocker arm, versus the cast roller rocker arm used later.

The difference between roller and non-roller cam pushrods is quite a bit though. Unfortunaly all I have left would be some later pushrods, to look at.

 

So of you that have done this swap, what head gasket set did you use (brand and price you paid).

What is the difference of using 3400 head gaskets and 3.4 head gaskets as far as quench height?

What spark plugs do you guys use (brand and gap)?

 

I used FelPro gaskets, no idea what they cost, I usually buy a bunch of parts at once.

Don't play off quench hight like it's nothing important, that's the reason why I recommend the thicker gasket when using the gen3 FWD pistons.

In my 660s I use AC Delco. If I'm just throwing the plugs in, I use about a .040 gap, if I have time to play I will usually go up to between .050 and .055 gap, if the engine responds well to the larger gap. This takes some testing though.

 

Can all of the stock brackets and accessories like the alternator, P/S pump, tensioner, idler, be reused or is there anything that has to be custom made/fitted? I dont have A/C or AIR pump so those are out of the way.

 

The bolt pattern on the end of the heads is different between the iron heads and the aluminium heads, however, usually a little slotting of the bolt holes in the brackets seems to get the job done.

When I installed my Franken60, I actuall had a new tensioner mount made up that also attached to one point of the alternator, since I moved my alternator down to where the A.I.R. pump used to be. For the power steering, I made an adaptor plate up, and milled the power steering bracket a littel thinner for proper belt alignment. Other people have simply slotted the hole here.

 

All gen3 engines use the same pushrod length, even the early 3100's.

 

That's what I thought I had come across, in my experience.

 

If there was a difference it was very slight, the part numbers of the 93-95 3100 pushrods have been replaced with the same numbers for the rest of the gen3 engines.


Kinda makes you wonder if all the gen3 pushrods are hardened...

 

Not really...

:P

 

I used Gen 2 pushrods in a couple builds and they worked, some they didn't. You have to check the pre-load upon final assembly. Unless two people are using the same exact cam from the same mfgr that were ground one after another, then the base circle will vary a bit, causing the pushrods to work/not work. Using RWD pistons and gaskets, the gen 2 pushrods seem to work better than than with FWD pistons/gaskets (which are .020" higher off the cam).

 

Hey Six Shooter, did you ever get my PMs?

 

I have, sorry for not replying yet, being in school full time and working almost full time leaves me very little time to do anything else. Once I get caught up on a couple school assignments, I will have some time to dedicate to going through my parts. I had hoped to get caught up this past weekend.