Twin plug mod

[Harpo]

Good morning everyone,

Can someone please give me a ballpark estimate to have my 1983 heads machined to accept twin plug with moderate porting/gasket matching etc?

Thanks

[75 911s]

Ollies lists prices on their website. Its not the twin pluging that cost all that much. It's the Ti retainers and AASCO parts and new valves that add up, plus the 3 angle grind. I think I have like 3400 in my 3.2 heads that I twin plugged.

[HaroldMHedge]

Craig Garrett (cgarr on this forum) converted my 3.2 heads for $300 to dual plug while rebuilding them last year.

I did not have it done but he quoted me $600 for Port and Polish of my heads as well.

Edit
Total head work was $1600 for rebuild, dual plug and 98mm cylinder conversion with new valves/guides and reusing what was usable (ex. springs and retainers).

['78 SC]

You will also need opening cut in the lower valve covers for the plug wires. Craig Garrett twin plugged a set of heads for me recently and included machining the lower valve covers.

[HaroldMHedge]

Thanks 78 SC for the reminder of the lower covers.

Craig also modified my lower valve covers at no additional charge since all the work was done at the same time.

[Focker]

I paid $1200 to have my heads rebuilt, new guides and twin plugging, including cutting valve covers.

I had to pay extra due to the corrosion and overall hazmat condition of the heads.

[Harpo]

Thanks everyone not as bad as I was expecting

[winders]

It's not adding the second plug holes that is expensive. It's all the other stuff that you do to the engine to take advantage of twin plugs that adds up!

[Mark Henry]

Harpo is working on a fresh build, he's got a lot the spendy bits covered.