4.0L Plenum Chamber

CastleMGBV8 · Post by **CastleMGBV8** » Wed Dec 26, 2007 10:07 pm

Does the 4.0L Plenum have a larger throttle body than the earlier plenums?

Kevin.

Eliot · Post by **Eliot** » Thu Dec 27, 2007 9:22 am

No!
The 3.5, 3.9, 4.0, 4.6 and even the TVR 5.0 are all 65mm!

http://www.mez.co.uk/ms12.html

I have a 72mm 4.6 gems plenum if you're after one.

CastleMGBV8 · Post by **CastleMGBV8** » Thu Dec 27, 2007 9:59 am

Thanks Eliot, I had a feeling they were the same size, but there was a 4.0 one on e-bay and I got it for £35.00. I believe you can have them bored out to 72mm with a bigger throttle disc, is that correct and any idea of the cost?

I'm just collecting parts for my 4.35L engine at the moment, having bought a crank from John Eales I needed a 3.9 bottom end and also got that off e-bay yesterday for the princely sum of £56.00, seems a good time to buy stuff as there wasn't much opposition.

As I have a pair of Buick 300 alloy heads, all I need is a set of the 5.85" heavy duty rods and a set of 305 Chevy flat top 3.736" chevy pistons and it should all come together at very reasonable cost and it should all fit together dimensionally without the need for any special machining if I've got my maths right! Can you think of any problems I might come across.

Kevin.