7mm vs 8mm spark plug wires

[usraptor]

A few months back I bought some Taylor 8mm spark plug wires for my '70 Cuda 440 converted to electronic ignition.  While nice wires, several are way to long.  I was considering buying a spark plug wire crimping/cutting tool to adjust the wire  length, but the tool is almost the same price as a set of new wires.  While buying some new exhaust header gaskets on Mancini Racing tonight I looked up their spark plug wire kits and noticed that Mopar Performance sells 7mm OEM type spark plug wire sets.  I assume that coming from Mopar that they would be the proper length and not require any trimming or cutting.  However, they don't say what year 440 they are for or whether they are for electronic ignition or a points style ignition.  For those in the know, will these be okay with my electronic ignition conversion, Summit Racing® Electronic Mopar Distributors SUM-851005 ignition (blue ECU?  Not that I think it will make any difference, but in case it does, the engine is a 512 Stroker with 10 to 10.5 compression, aluminum heads, Holley dominator intake and QuickFuel 880 CFM Carb with vacuum secondaries.

[redgum78]

I can't say if the leads will be perfect length or not but I can say I did not regret buying a plug lead crimp tool. Almost every set of aftermarket market leads I have brought have needed adjustment.

[Chryco Psycho]

It is not so much the thickness that matters as it is just extra silicone , but you want a high quality sprial core whick n\most 7 mm wires do not have .
I always buy universal kits & trim to fit properly

[Bullitt-]

Mopar performance wires for my small block were so ill fitting as to be unusable(short), I exchanged for MSD 8MM made to fit set which were also disappointing, they sent me extra wire & terminals which included this tool which works in a vice https://www.summitracing.com/parts/msd-3503 to resolve my issues.

Lotta folks I see are recommending Firecore as the best alternative for a good fitting/quality product 
https://www.customwiresets.com/home.php?cat=299

[Burdar]

Mopar performance wires for my small block were so ill fitting as to be unusable(short)

The small block wires are pretty crappy.  I was able to use them but a couple wires are too short.  They could have been an inch or two longer and the kit would have been fine.

I haven't used it yet, but I bought a plug wire crimping tool to customize my universal wire set.  It's just an aluminum block that you use with a bench vise.     
The actual plug wire pliers were pretty expensive.  The aluminum block was less than $20 I think. 

[303 Mopar]

Lotta folks I see are recommending Firecore as the best alternative for a good fitting/quality product 
https://www.customwiresets.com/home.php?cat=299

I have Firecore 8.5mm from Mancini on my 505 stroker and they fit really nice, and come with good quality boots!

[usraptor]

Mopar performance wires for my small block were so ill fitting as to be unusable(short), I exchanged for MSD 8MM made to fit set which were also disappointing, they sent me extra wire & terminals which included this tool which works in a vice https://www.summitracing.com/parts/msd-3503 to resolve my issues.

Thanks everybody I bought this crimping tool along with some new Taylor distributor caps fittings.  I appreciate the advise, as always. 

[61K T/A]

The MSD wires I bought include the crimp tool.

[Roadman]

    That crimp tool really makes the job easy. I think I have 2 extras if anybody needs one, just pay ship.   

[nsmall]

I had the same problem on my stock small block as Burdar.  WAY too short.  I had to return them.   Good luck.

Neil

[chargerdon]

On my small block (360) i also found about 4 of the wires to be too short.   However, i also found that by taking the distributor out and rotating it 180 degrees, and then the cap also 180 then i never had to run a wire "across" the distributor to the other side, and they all then fit....   i.e. now no wire runs to the opposite bank.