Carkhz316's Topswap Thread: IT RUNS pg5

[carkhz316]

Getting ready to do it finally guys and girls! As I mentioned in bumping my "Want L67" thread, I finally obtained a complete L76 out of a 99 GTP for $150. I got a complete Fel-pro top end gasket set, though I'm ordering the Permadry Plus metal intake gaskets as the kit came with the plastic ones. This project will hopefully initiate very soon, as my wife and I are in the process of buying our first home. (More on that in another thread). I'll have a nice two car, heated/insulated garage to work in now. But yeah, about the engine stuff:

 

I want any of your's inputs and/ or suggestions regarding the topswap. Any tips or tricks or secrets that I might not know about?

 

I know I have to get a PCM yet, which I'll probably do through ZZP.

 

I have had a malfunctioning PC solenoid in my trans since I've had the car. Thinking of replacing it when I'm in there. Will it be any easier with the top half of the motor out of the way? Of does one still have to drop it down some to rip the side pan off?

 

Do I have to swap cams? I've heard and read it's not necessary.

 

Also, I'd like to upgrade to the HD differential? Can I do it with the trans in car, or do I have to yank the trans out as well? Anyone know best place to obtain HD diff?

 

I'll think of anything else as time goes on. Thank you all for any help and whatnot. This site has always been helpful;)

[Dark Ride]

I personally would swap cams, I know there are some differences, and a L67 cam is made for boost. Let me know if you want help with this project!

[AL]

I have never heard about them being different cams

[White93z34]

if there is a difference in cams it is totally minimal. not worth the work to swap a stock cam for a stock cam IMO.

 

the engine in digitaloutsiders regal gs is a l36 with the l67 stuff bolted to it. its been holding up fine for a few years now.

[alec_b]

If you're having trans. trouble do yourself a favor and just take both out. The PC solenoid and the HD differential are both easier to install with the trans out, then you can replace all the mounts easily also (good idea). I'm not 100% sure, but to swap in an HD diff you may need to change some other parts also. Someone will chime in.

[White93z34]

to do the diff swap you need the axles too.

[Dark Ride]

It would seem that I am mis-informed. Having not actually done this swap myself I cannot say for sure, but I am surprised that there wouldn't be differences.

 

Here is a kit from ZZP for swapping the HD parts in, but you could probably get the parts cheaper used.

http://www.zzperformance.com/grand_prix/products1.php?id=394&catid=105

[alec_b]

That's right I forgot about the diff covers are different. So it looks like you need to find a donor 4T65e-HD and get the passenger axle, the diff, and the diff housing.

[AL]

The axles are different!!!! Damn

[carkhz316]

Thanks guys. I'm on the fence about about ripping the trans and engine out to do it. The tranny isn't really giving me trouble per se. It's just anytime I've had it between 3/4 and WOT that it shudders on the 1-2 shift. Thats it. No other problems. I'll probably drive it for awhile to see how she handles the blower. I plan on rebuilding it down the road anyway, but I don't think I have the funds for all the trans stuff (TC is really fricking expensive compared to the rest of the rebuild parts). Thanks for the link Mitch, though I may hold out for a used/ blown up trans.

[Andrew]

i'd hold off on the trans upgrade until you start moddin and/or do lots of hard launches.

[Addicted to eaton]

If it was me... Id do a trans upgrade.

 

The point of higher compression is not needing the boost to make as much power as an L67/L32 car. the l67 have a lower compression the the Naturally aspired 3800.

 

You make as much power on a Top Swap with a 3.8" pulley as a regular GTP would make on a typical 3.4" setup. That means The No HD trans. Behind something more powerful then an l67. Well.. Id HDalize it.

[Euro]

There are plenty of people that are top swapped that aren't running an HD trans that are fine...even WITH mods. I think you should be alright for now if you want to save up for the HD rebuild parts and whatnot. Just don't drive like a tool and stand on it from a stop, burnouts, or the ol' flooring it with the wheels turned and you should be good.

[carkhz316]

Ya, I don't plan on driving foolishly, or even racing. I cringe at the thought of having the wheels turned and attempting to burn out as I realize the great amount of strain that puts on the drivetrain. I don't really plan on doing much for mods other than some sort of intake upgrade and headers eventually.

 

Will I be safe running the stock (assuming it's stock ???? size) blower pulley, or will I have to slap a bigger one on to keep boost in check?

[Addicted to eaton]

If it were i. I would throw a 4.0 on. Scan for KR, If your ok then dont worry about it. When i did the top swap on my 97 GT. I had to throw a 4.0 On it, with still 2*KR at WOT. I lived with that. But every car is diffrent. But I would get a 3 inch downpipe,ubend delete, a FWI, a Tune and a t-stat and 104AL plugs.

[carkhz316]

I know the pulley has been a big concern of mine about what one to run. No u-bend to worry about as the monte's didn't come like that in 98-99. I wonder how big the DP is; thought it was closer to 3, but will have to check into that.

 

Not to sound dumb, but I have no idea where to go or what to do with tuning. I can do everything else, even the wiring in a car, but don't know the actually programming. I can read everything on a scan tool and know what it's about, but know nothing about tunes.

[Addicted to eaton]

well, If you have a local member around you that can tune? Look on Clubgp. see if they have a local chapter. as in DP. i think its a 1.5 on the inside..

[Euro]

Yeah a DP for sure, they're pretty tiny stock. And what Anthony said, look on your local GP club site, or even the Monte boards to see if there's someone close to help you out.

[carkhz316]

Bump. Got stuffs ripped apart. Heads are off to the machine shop to get checked over for cracks and whatnot.

[Euro]

Nice!

[Dark Ride]

Looking Good!

[jtwmechanic]

perfect time to grab a blower kit from zzp and freshen that thing up, and get some sc oil and make sure its clean and full. check the tolerances on the sc coupler and change it if needed. both kits and the oil will only cost around $50-$60 without shipping. cheap for a rebuilt blower. if its at all possible get some ls1 springs and have them installed while they are at the machine shop and have a 3 angle valve job done too. just run your stock pulley and get a tune and as for the dp, have your local muffler shop make one its cheaper. oh and get new head bolts and some anti-seize.

[carkhz316]

perfect time to grab a blower kit from zzp and freshen that thing up, and get some sc oil and make sure its clean and full. check the tolerances on the sc coupler and change it if needed. both kits and the oil will only cost around $50-$60 without shipping. cheap for a rebuilt blower. if its at all possible get some ls1 springs and have them installed while they are at the machine shop and have a 3 angle valve job done too. just run your stock pulley and get a tune and as for the dp, have your local muffler shop make one its cheaper. oh and get new head bolts and some anti-seize.

Thanks for the tips. I'm definitely changin the SC oil; but the coupler seems tight, so I may or may not get the new bearings and whatnot.

 

Those LS1 springs are always sold out everytime I've looked on ZZP.

 

Probably won't touch the valves if they are alright.

 

I have a 98 Z34; I thought I read somewhere that the downpipes are suffient in size for flow from the stock 3.8??????

 

I've been doing some reading about tuners and whatnot. All the data that everyone is looking for is all old hat for me. I'm use to looking at it on Live Data displays on scantools; just never been able to modify 'em. If that's all that's too it, then what tuner would any of you go with? And just need a laptop right??

 

Thanks people! Will keep all posted with ma progress.

[carkhz316]

Update. Had a call last week from the shop. One head (rear bank) had a crack between the seats on one cylinder. Found another pair on CL a small drive from me. Got a 3800performance computer setup for a topswap (pretty sure, or stockish L67) with the heads for $100. Brought the heads in this morning to have them Magnafluxed. Front one had multiple cracks between valve seats. Rear had two, but they were so small, that they could barely be seen even with magnafluxing. Shop guy said they could last a day, or ten years. I know I'm going against good judgement even thinking about using the "bad" one. Are all L67 heads this easily prone to these type of cracks? What have you top-swappers done or what would you do? Anyone have a pair of good ones (or at least the rear bank head)?

 

Cleaned up most of the rest of the other parts. Want to paint most of it. (I know, RICCCCCCCCCCCEEEEE) But it will either be black or silver for everything from heads on up (minus a polished blower). Have mothers ball; and air drill; will happen. What type of paint have any of you used, or recommend? (I know, high heat engine paint, but particular brands and whatnot)

[Dark Ride]

If you are just using rattle can paint, I've always had good luck with rustoleum. And FWIW, I think that a painted motor/engine bay looks good.