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Hi, first post as a new member!

I bought a 1973 Pantera L in March which had been converted in period to GT5 specification and fitted with original Campag Magnesium Group IV wheels. It then underwent an immaculate nut and bolt restoration about 25 years ago and then lived in a private static collection.

I spent about GBP 10,000 on having the car fully recommissioned mechanically (The interior and body are still A1). Now, the one area we didn't touch was the internals of the engine but it seemed to be running okay on a rolling road.

Long story short is that 15 miles into the road test, the car lost all power. Investigation shows that the Push rods and rockers had not bee correctly torqued down at restoration and had decided to leap around inside the engine. It further turns out that this is not a Pantera Cleveland fitted but a 351C Cobra Jet from a Mach 1 Mustang.

So I want a new engine but what to go for?

I want a 351 and am more swayed to a Cleveland than a Windsor although I have been offered a 'Clevor' hybrid of the two.

Firstly, how much power is too much power. I want an upgrade on standard but I don't want to sit there fizzing the tyres in something undrivable. Numbers being quoted by engine builders range from 370, 390, 420 and 450 bhp. I definitely do not want more than 450 bhp but I have a feeling that say 390 bhp would still be outrageously quick. Whilst some builders stick with the 351, others stroke them out to around 400 c.i.

some advice would be very much appreciated. I have spoken with a US company (Barnett High Performance) but I am swaying in the direction of a UK build lest it develop problems in the future and am therefore speaking with British American Engines.

So, how's that for a big first question!!! Many thanks in advance, Tom
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First a clarification. The oem motor for a 1973 Pantera is a 1973 351C 4V (i.e. Cobra Jet) motor. What the Mustang guys call a Q code motor. The exact same motor found in a 1973 Mustang. 8.0:1 compression ratio, Autolite 4300D carburetor, exhaust gas recirculation, dual point distributor, cobra jet camshaft indexed 4 degrees retarded from the 1971 specification. The heads have big 4V ports, 78cc open combustion chambers, 2V size valves, and the pistons are dished.

Second, if it were me I would fix the engine you got and minimally modify it to achieve 400 to 450 bhp. That's an easy goal to achieve with a 351C. Raise the compression, port the heads, install a better cam & matching valve train, and finally induction system and exhaust system improvements will do it. I won't go into detail here.

Thanks to George and no worries, I have spotted your building engines thread so will pass this on to my engine builder. What power should I be looking for? I am keener to have a revvy engine than a tyre-smoking torquey one.

How do I go about finding out what my original engine number is? I had assumed since this was a Cobrajet, it was the wrong one but perhaps it is not.

Thanks for the complements on the car Jim. It really is quite exceptional. It used to be a racer and then underwent conversion and then hibernation. The interios is beautiful cream leather with perforated blue leather inserts, blue carpets trimmed in cream leather. All the arches and engine bay have been smoothed and body coloured, nickel suspension etc. How do I post pictures?

Thanks, Tom
I would also have to agree with George. I have a a 72 with GT-5 upgrade. I went with a bore and stroke to 393ci but kept the 4V iron heads, put a nice roller cam,rockers, stainless steel 1 pc valves, new intake and big bore exhaust. I am at 500hp and have more than enough power. Infact 500hp is enough to get yourself into trouble if you are not careful. Even with 14inch of rubber on the ground you have to manage the throttle.
Best of luck, looks like a nice car
Hi Tom,

Nice car. I had the same problem, and started to collect parts.No I go a differend way. If you made your choice, and you start buying parts, I have a brand new high performance harmonic balancer. BHJ, top end and racing approved. Heavy expensive piece to order in the states. I brought it in myself, so it is reasonal priced. If intrested, just sent me a PM.

have fun with your pussy, Arno
Nice car - lets see more pics!

How much horsepower is too much? Over 700.

I have been down that road and worked my way up from 350 to 525. There's very little difference in drivablility but a big difference in fun.

The ZF can handle 600 with the basic config and good half shafts. And 525 hp is very steetable with 10.5 compression. Since you're starting from scratch, keep in mind that you get used to HP real fast.

Less is less. And more is more. Period.
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