Engine / gear box choices

[Allen]

I am trying to make a decision on a power plant for what I will hope power a RCR MKII GT40. I have done a small amount of investigation over the years and before getting started would like to get some opinions of the power plant and gear box.

My plan was to build a mild 390FE around 400 or less HP with a G50 gear box. Some concerns I have are;

- FE in a MKII; over heating issues, other unknown problems? I only ask because I never see it done, almost always a SBF even in a MKII.
- Money. A G50 gear box is going to set me back about $5k not including starter, diaphragm and clutch which is going to be about another $1,000. Correct?
- The G50 will attach to the 390 I assume with an adapter? Such an adapter exists correct? How much? Reliability issues?
- is this a bolt up adapter to engine to gear box or something else entirely?

Any comments would be appreciated.

 

[Will Campbell]

Why use a 390 with so little power when small blocks are easily available with that much power, much lighter weight, and fewer fitment problems?

My fantasy RCR 40 would have an aluminum SB Ford block, with forged internals, stroked to 347, and topped by a Weber-look FI setup. These could be made into a 427 if that's what you need- and for much less weight than that iron lump of a 390.

But that's just me.

 

[Tim Kay]

Then Will, your wish will look something like this and Allen, the G50 attached has been most reliable mated to the the 427W (Kennedy adapter)

 

[Allen]

Are there fitment problems? I hear your comments and there is truth to what you say, but one my own fantasies was to build a FE, put it in a car that calls for it (a car that originally had one).

I think your fantasy engine with specs you note is going to be quite a bit more than a slightly heated up 390FE. A quality stack injected setup is going to run you what? 4 to 5k alone? 2k for the block? More? Yes, if I had an unlimited amount of money I would want something different too, including a 15k transaxle.

I will sacrifice what I want for better reliability, I just want feedback from the people who been there, done that.

I appreciate the feedback.

 

[Allen]

Tim,

Thanks for the posts, I have seen that beautiful setup before - yours looks great. But my dreams (minus any reliability issues) are an FE with are large manifold and Holley.

I have a 408w with 48IDAs on my Cobra, looks great and it is very reliable. The questions I have are specific to the setup and costs of the mating of an FE since I never seen one on a GT40 and wish to confirm the costs. Perhaps there is a great reason for it, that an MKIs came with a 302.

I am not set on it though, just need the feedback. I don't have the money to build the car the way I want with a stroked 351w so it will either be a 390 or 347 SBF.

 

[Howard Jones]

If it's in your budget, why not a alum FE block and heads? It will be near the low weight of a iron 351 block and fill your need for a FE.

Kennedy can adapt an FE to a Porsche. How about a 930 4 speed? Kinda gets you back to 1968 or so. At least in basic design parameters. Big block/4 speed in a MK2.

Cool car. Do it.

 

[Alex]

Can a porsche transaxle really survive a big block? :worried:

 

[Allen]

My question exactly, amongst others.

 

[Bill Musarra]

I am not aware of any failures to 930s. I am sure someone will chime in if that is incorrect. The 930s have been put behind all sorts of combinations and have withstood it all, some of them dedicated track cars. So unless some one knows of a failure, that would be a great choice. The windsor engines are great for pulling power out of. Its my choice. When I get my electronics sorted(hopefully this month) I will report the numbers of a 396 Windsor!!

Bill

 

[EGLITOM]

Allan

Fe will fit, Adapterplate will be delivered with the KIt, G50´s will survive a max 450 lbs ft 390.
If you go higher it calls for modification or the stepup to a turbo version ( G50/50, G50/52, G96/50 order the 930 4 speed which would also be a good visual match to the original carcraft t44.).
Headers need to be custom made ( Kit comes with 302 fitting exhaust system).

TOM

 

[Allen]

Tom,

Thanks for the reply Tom. Aren't you using a G50? If so how are you getting by, how is it performing?