OK some one let me know if i have all this right, so you can swap a Gen III topend on to a our Gen II engine. But if i do that i have to use the 3100 pluntums and do some other minor modifications.
So the Gen III heads won't bolt to the Gen II 3.1 pluntums.

What if i just port and polish the stock heads on my 3.1 and use the rockers off of the 3100? keeping the origional push rods?? that will work right?  so all 3100's have 1.6 rockers right?

I have a complete 3100 engine out of a 00 Grand prix, and i have my car all taken apart to do the head gaskets, so i guess from what i been reading i will just use the rockers off of it cause i don't feel like doing all that work to use the 3100 heads.

But for those of you who have converted to the Gen III topends, was it really worth it cause it sounds like a pain in the @ss?



~Dan
89 TGP
97 Z28

QuoteBut for those of you who have converted to the Gen III topends, was it really worth it cause it sounds like a pain in the @ss?

I would sure as hell think so :shock: though I can't speak from experience on the matter. yet.

I guess I don't understand exactly what you're asking.  You want to use JUST the 3100 heads and not the 3100 intakes???  Or you want to use the 3.1 heads and the 3100 intakes.  Either way, you need to use the whole topend from one engine, you can't put 3100 heads on a 3.1 and have everything else work.  The rockers arms have nothing to do with it not working or not.

If you already have the engine apart anyways, and you have a completely 3100, just put the whole topend on it.  There isn't THAT much that has to be modified.  I could sit here and explain to you what needs to be modified, but once you start putting the engine together, assuming you have basic knowledge of how the engine works, you will be able to figure out what you need to do.

And as far as is it worth it?  I don't know about just the topend.  But with the combination of my topend, cam, and ud pulley I gained ~5mph in trap speed in the 1/4 (based from my G-tech pro) and 7+ tenths, which makes it more than worth it to me, and I have a '97 topend with '95 heads, so yours would be better because you have the bigger intakes and bigger valves.  It has more power everywhere, low-end, mid-range, top-end, there is just plainly more power everywhere.  The difference is very noticable, and the 3100 combined with a turbo upgrade would give you HUGE gains.  Once I get bigger injectors on the car, get the boost where I want it, and tune it a little, I would guess that I will see at least a second in the 1/4.  Low 13's should be easily possible with a turbo upgrade in addition to the topend.

Shawn

yeah i wanted to use the 3100 heads and rockers with the old 3.1 intake casue i wanted to keep the stock look to it. cause it says "turbo" on it ya know...

what about a 3400,would the 3400 top end work too?   cause i also have an engine out of a 04 Grand Am with a V6. IS the 3100 and 3400 top end the same??     cause i rather use the 3400 engine and intake since it has like 1000 miles on it and the 3100 has alot more.  and while i had this apart i wanted to put 1.6 rockers on the engine but i don't want to buy them if the 3100 or 3400 already has them.

So i was just wondering, will everything ELECTRONICLY from the turbo car just plug right in to the 3100 topend? or do i have to do some wireing to make it work? and i have to use the 3100 throtle body?  will all that vacume junk on the top of the stock throtle body hook up to the 3100 throtle body??

Air TGP check PM

what?? check PM??

oh duh i figured it out

http://www.domesticcrew.com/660/  

should have more answers for the 3100 / 3400 top end swap

I'm tenatively planning on using the 3500 plenum on the 3400 swap.  I'll prolly use the 3400 plenum first to baseline, then see if the 3500 gives any gains or losses.   I'm been watching the yards lately for the 3400 I need.  When Sunshine comes apart for the tranny work, she'll be getting a 3400 top end, and prolly a complete refresh on the bottom side.  Unless I get the cam out, and it looks like hell (like I suspect) in which case I'll just do the topend, and cam.

What exactly would someone need for a 3x00 topend swap?

How much are we looking at to do a 3x00 topend swap?

What kind of hp/tq numbers could be expected?

Quote from: god910I'm tenatively planning on using the 3500 plenum on the 3400 swap.  I'll prolly use the 3400 plenum first to baseline, then see if the 3500 gives any gains or losses.

The 3500 plenum looks like a really good setup for a turbo car, since it's basically an open plenum.  I've been comtemplating a topend swap lately, but I think I'm updgrading my turbo first since .68 A/R turbine is really holding us back. You can pick a brand new 3500 plenum for around $115 from GM parts direct.   8)

Sweetass, I was worried it was gonna be more.  Yeah, I've been lookin at it for the best gains, the only downside is that it's not a direct swap.  The biggest factor is that it looks like the TB points down WAY to far, especially to have a turbo sitting there.  The only people to use it (only 1 that I know of so far) is N/A, and it looks pretty bad.  But, hey, I have the means to weld aluminum, so I guess it's not that far off.  I'll be doing the 3400 swap and the turbo swap at the same time, so I'll know what I'm getting into all at once.

Yeah, from the pictures on 60degreev6 forum it looks like the throttle body might get really close to the turbo.  Then again, I thought the same thing about the 3X00 topend swap.  :roll:

Quote from: skalorYeah, from the pictures on 60degreev6 forum it looks like the throttle body might get really close to the turbo.  Then again, I thought the same thing about the 3X00 topend swap.  :roll:

If its any closer than the 3X00 we will have MAJOR problems.  My intake tube (from the IC to TB) actually rubs on my 02 sensor because the 02 sensor kind of blocks the TB.  The TB is only about an inch, maybe an inch and a half above the turbo and where it ends up the 02 sensor is actually partly blocking the TB.  Although, if you relocate your 02 sensor (like you would with a different turbo), and the TB doesn't end up more than like 3/4" lower then it will work from what I can see.  If I had any money, I would consider doing that swap to see what all needs to be done, since it would be a lot easier for me to do than most everyone on here.

Shawn

dbtk2...do the 3100 exhuast manifolds bolt right up to the crossover??  also the 3100 had a higher compression ratio (bad for turbos from what i understand) doesnt that cause knock??  what length pushrods did you use??  how would you rate this project difficulty 1-10, and what experience level should one have before attempting this?