funtoy

Greetings,

I'm looking for suggestions for my distributor.

I have a 85 coupe with a new 350 , Vortec Heads, Scoggin Dickey Intake manifold for the vortec, 58 BBK throttle body. I'm going to keep the original TPI set up, just looking for a more consistent spark.

I am thinking about the MSD 8365.

https://www.msdperformance.com/produ...let/parts/8365

What about a digial or analog box as well?

eutu1984

that disy will not work with your ecm.

funtoy

I did quite a bit of research, talked to a variety of NHRA Supercomp & Top Sportsman, as well as a few Vette techs. Although they say It will work, I suspect something else. Can you inform me what would specifically work with my new engine running stock runners, stock TPI and a larger dual exhaust. Thanks for your time.

Tom400CFI

The stock distributor will work the best, with you combo, IMO. Your combo is in no way, "taxing" the stock ignition system. If you're getting inconsistent spark, then there is a problem that needs to be diagnosed.

eutu1984

either the stock distributor or this https://www.summitracing.com/parts/dui-12611bk will work with your computer, you can use the msd unit you supplied a link to but it will not allow the computer to have control over it, instead it will be mechanically controlled and vacuum controlled.

aklim

In what way consistent? Is there something wrong with your spark? I suppose if you take out the distributor and found it was worn you can switch to an MSD8366 and mount an external coil and get a simple harness made for it. Bottom line, what are you trying to achieve?

RWDsmoke

[QUOTE=eutu1984;1593546436]that disy will not work with your ecm.

And the fuel injectors will not fire without the signal from the distributor.

funtoy

Hello everyone. Thanks so far for the input. @ Aklim, I am not sure what I meant by consistent.
I am a newbie and just trying to learn. I am relying on a colleague from work who is a top sportsman NHRA racer, he has built and installed several hundred engines over the last 10 years.
I have never previously owned a corvette and this one I currently own I have never driven. When I purchased the car last January, I bought it as a roller. I have the original engine, but I had another 350 already built waiting for a Camaro project. I have since dumped the Camaro and am fully vested in this corvette. I intend to build the car as close to stock as possible.

The original distributor is cracked, bent and covered in oil??? So if that specific MSD won't work what about another option.

I have found this MSD Ignition Harness 8875 which is to install late model MSD Box..probably 6Al on late model cars.

What about a distributor that will fit under the TPI cover. I've noticed in some pics, builders leave off that small cover over the distrib?

Tom400CFI

Another stock distributor will work fantastic.

aklim

Lets see what symptoms you are having and try working it back from there? You say it is cracked, bent and covered in oil. Do you have a picture so we can see if it is the cap or the distributor itself? If it is the distributor itself, you have no choice but to get a new or rebuilt one. If it is the cap, we need a new cap and rotor to even start the diagnostic process.

Either a stock replacement or an 8366 with an external coil will work. You don't need an MSD box.

blackozvet

The 85 computer controlled TPI / EFI distributor uses a 7 pin module that has a 4 wire loom coming in the back from the computer, one of those wires is the one that sends the message to the dizzy to advance and also retards if it detects knock sensor activation.
So effectively you need the same type of dizzy to replace it.
you can get rebuild kits for the top of your distributor if the shaft and drive is ok.

VikingTrad3r

another vote for oem or equivilent.

kenmohr

have one for sell if you are interested. Should fit an 85. Pics on request.

gmjr

on my 1989 i ran the stock distrbutor with a msd 6a box and a external msd coil they make a dist. cap that fits the stock distributor, that 6a box is a like day and night compared to that stock ignition as to where my car would bang out between 4500 and 5500 rpm I could run the rpms up to whatever.

VikingTrad3r

i thought it was airflow through intake that gassed us out. not spark.

aklim

That is interesting. On my stock 91 Firebird with the L98, you can run it past 6000 if you want (not that it made power that high). The only difference was that it has a small cap distributor which is essentially what you have. Currently, I am running an 8366 distributor with a coil outside of the distributor and haven't noticed that problem. I have run the ACCEL version of the MSD in my Firebird but didn't see any real difference. Transfered it to the Vette and when it didn't do anything but have a rev-limiter, I sold it.

I didn't think the big cap distributor was that inefficient but I didn't drive a car with it other than to get it off the trailer and a bit around.

gmjr

hello funtoy on my 89 I was running a p600b procharger and it ran out of rpm at around 4800 rpm it didnt actually bang out,but when I put the msd on I started running it up to 6,000rpm easily with rpm to spare. so I WOULD SAY THAT SPARK DOES PLAY A BIG ROLE IN RPM LIMITATION.At the same time similar cars respond differently to the same modifications .

aklim

What about if you didn't have the procharger? IOW would it make a difference on a stock system? I didn't see it on my NA L98 engine even with higher compression and a different intake and head.

gmjr

should make a difference regardless of setup msd box makes makes a much fuller spark which definitely gives you a better fuel combustion and better and faster revs.

gmjr

its still a big cap distributer it just has a provision on the side for a coil wire.