IshouldNOTbeHere

Hey, I recently acquired this 1984 with the 4+3 trans:




Anyway, to make a long story short, I'm in the process of cleaning it up a bit and trying to have some fun out of a driver. Well, I let somebody else drive it on Sunday and they thought some burnouts would be a sweet idea. The engine did not think it was so sweet because now it sounds like a connecting rod is shot.

So my plan for performance upgrades has to be put to the front of my priority list suddenly since it's time to deal with the connecting rod(s).

I have not pulled the engine yet because I'm still trying to plan what I want to do.

One thing is for sure, I hate the 4+3 transmission. It's not for me. I can see the appeal, it's neat, it's a gimmick but I just prefer the old 6 speed box. The previous owner put this 4+3 in from a 1985 or newer Corvette so it's not the original. It's in good shape and it only has 6X,XXX miles on it so I will be selling that transmission. I want the ZF6 and my understanding is there should be no major fitment issues in the 1984.

So that leads me to what to do about the engine. I'm looking at stroker kits as I try to keep the cost down. I am, of course, going to ditch the crossfire intake for the Edelbrock SY1 intake. Sorry to the crossfire fans out there but it's just not for me. I want my **** to breathe.

So, can it be done on the 1984 ecm if I ditch the crossfire? What do I need to know? For example, I read this thread a bit: https://www.corvetteactioncenter.com...ion-383-a.html

but I want to do it even cheaper than Grumpy Vette suggests. I can find cheap stroker kits on ebay for $400 for example. I know they still need to be balanced and some other things, but that's ok. My goal is budget here because this happened unexpectedly and I want to get back on the road while addressing the crossfire and 4+3 issues while I have the prime opportunity to do it all at once.

This is my first Vette and my second Chevy (Suburban). I've wrenched on a lot but I'm mostly a Mopar guy. So I'm trying to learn what I can and can't do and this crossfire system has not made it any easier.

cv67

Gotta love friends like that let me guess he belched out "I can drive" watch this!

Check out the Renegade intake on Summit good value for the gains

You can do a cast bottom end stroker for not a lot as youre not spinning it up high. Get the best cyl head you can, headers so it can breathe
Cam....watch the overlap on it!!

Couple guys really know these well they can guide you to whats worked for them (not something they read).

Kevova

Thats a lot of project's at once. The 84s all had D36 rear ends which can have problems with HP engines and burn outs. D44 which is found in 85-96 M6 cars is a better choice. It's unlikely you will find a "$400 stroker kit". You could try to find a used SBC 400 to rebuild with a cam and and better heads if budget allows. In regards to ECM and harness you don't need then for engine to run but it does share info with cluster.

IshouldNOTbeHere

So, if I went to the Renegade intake, would the system play better with the usual performance mods done to Chevy 350s?

IshouldNOTbeHere

Oh I definitely found a stroker kit for $400: http://www.ebay.com/itm/Chevy-SBC-35...pXHf7Q&vxp=mtr

But it's not forged and some other things.

I did not know this 1984 had the D36, are you absolutely sure on that? I thought the 84 manual trans equipped cars had the D44. I was told this by another Vette guy so I'm confused now.

ovrebo1

I haven't looked for one, but from what I have been reading the ZF6's are like $2k give or take, for a used one. Were you aware of that?

IshouldNOTbeHere

Well, I actually have looked at them, a lot. The actual prices on them are $900 to $1500 and like I said, I'm going to sell the 4+3 to offset that cost as well. The 4+3 is rare and also worth a pretty penny.

Gibbles

look at dynamic efi, it will support all sorts of options.

Either keep the crossfire and add the renegade intake, heads, cam, exhaust, add a set of injectors from a 454 big block...
Or swap to a different setup, lots of options there.

You will need a fuel pump upgrade either way, the 84 pump was weak...
That's a quick and easy swap.

I also had to upgrade the grounds at the rear of my car for the added fuel pump, after swapping my car would not run for longer than 10 seconds...

divotdug

I have an '84 4+3, all my research indicates it is a D36 rear. The D44 did not start until '85.

I've also researched various transmission swaps in the event my 4+3 fails. I'm not sure the ZF6 swap would be worth the effort.

I can rebuild my OD unit for much less time and money or possibly just go with a T5 out of an older F-body vehicle.


In response to Gibbles, I swapped my pump to an '85 pump and have had no issues.

cv67

That is an external balanced assy so youd need a 400 balancer and the right FW. Looks like eagle SIR rods?


Yrs ago there were a bunch of brand new ZF trannies being sold for 1500 dont pay a ton for a used one. Will say one thing they are a stout piece you wont break one

Maybe get ahold of ZFDoc see if Bill may have one laying around.

T5 could be an option indeed long as you arent clutch dumping or power shifting oughta hold up Ok. Dont worry about the D36, run it...may last indefinitely or not. Some D44s are real reasonable out there, some will bend you over for some worn out junk. Take your time looking

IshouldNOTbeHere

This is awesome information and very helpful, thank you! I'm leaning towards the renegade option right now. I guess my first step is to pull the motor and see what exactly got a little too much mustard. From there I will probably be heading somewhat in this direction.

What more can you tell me about dynamic efi? I understand the car can run without the ecm but I'm curious why you suggested dynamic efi and how that ties into the crossfire (if it does contribute directly at all).

Thanks a lot on the fuel pump tip! I will try to locate one right away!

IshouldNOTbeHere

Thanks for this helpful information! I will take my time on the D44. Is ZFDoc one of the users here? I'm definitely in the market for a ZF6 if he is around here and if he has one he is willing to sell at the right price. How much do you think a fair price for one is?

pologreen1

ZF6 complete conversions can be had for 1k-1500, but... the expensive part is repairs on them.

t56 magnum is the best for holding power. For what you are doing a t56 would work fine and easier conversion, but the 4+3 is a t10 and is okay too.

someone here was selling me complete zf6 stuff for 800. Vendor though, keep that in mind... with computer too.

pologreen1

d44 forsale here right now with decent rare 3.33 gears. used to be desirable. Be good with your trans.

Gibbles

Google dynamic efi, look at their site and do some reading.

The thirdgen also has a section devoted to tuning.

I have not gone down that road yet due to a blown transmission, i just completed my third attempt at getting it right... Lol
Fyi never put a universal tv cable on an 84, ecklers sells a proper tv cable for the 84

I have a set of reworked edlebrock heads, better camshaft, amd a set of 1.65 ratio ratio roller rockers to go along with my new intake.
A total of .500 lift

I also added a new exhaust system, long tube headers with true dual 3in exhaust (melrose brand)

With the larger injectors and my fuel pressure bumped up it's running decent with the stock computer...

For the dynamic efi setup you do have to tune it your self, they give you some base bin file to start out with, th'en it's all tweaking it from there.

With the setup you get a much better processor with better resolution, what that means is it has the ability to run your engine better and more constantly than the stock computer ever could.

That said there are cheaper options, that and with an 84 you also have to do some wiring to adapt the new computer.

The car now has an actual powerband where i would loose power before, totally different beast now!

cv67

http://www.zfdoc.com/

Hes a busy guy so may have to leave more than one message.
Knows his stuff when it comes to these trannies maybe hes got one laying around?!

mtwoolford

nice project; to maximize engine smoothness, have the whole rotating assembly, including the balancer/pulleys and flywheel balanced as a unit

IshouldNOTbeHere

Hey everyone, you guys have been really helpful and I want to say thank you for all the help so far.

As has been mentioned, there are so many options! I have two brothers with LS motors (C5, GTO) and they are really pushing me to do a 5.3 LS conversion with a T56

I've also kicked this idea around: http://www.hotrod.com/events/coverag...c-small-block/

On top of the ideas already discussed in this thread! So, I have some more thinking to do and some more decisions to make...

C4+3=/=C7

Not sure how the 4+3 is a "gimmick," but if I were to make a switch I'd look for a Richmond 6 speed. Best gearing, lighter than either factory manual transmissions, and most straightforward to install. AFAIK they are no longer being made, but I've seen them for sale in a few places; they might be left over stock but more likely are listed by accident. There have been a few users who switched to the ZF6 from the 4+3 that I know of and the TKO seems like another good option. I have seen a lot of threads where owners gave up on T56 swaps due to incompatibilities and complexity concerns but they have been done.

IshouldNOTbeHere

I didn't mean to offend anybody, like I said, I can see it's appeal but it's not like it's something that stood the test of time so yes, I view it as a gimmick. If a 2017 comes out with a 4+3 then I will eat crow.

Those Richmonds are nice from what I've read about them. Not sure I'll have that kind of cash when it comes time to buy a trans but if I do, I'd probably get a Richmond for sure. The ZF6 makes more sense to me than the T56 but if I do end up going with an LS block I would probably choose the T56 even though I know it will have it's obstacles.