Is it worth putting in a 427 side oiler?


I've installed an FE in my car with the 930 trans-axle. It's a tight fit and the exhaust had to be routed with a bit of imagination but its in. The alternator and the compressor will be tight as well but it looks like it will work without opening up holes in the tub. Fran told me the biggest issue will be the heat and of course it won't be as nimble as a small block. It's going to be a street rod and nimble isn't greatly important. My biggest concern is there being more car than driver. I'll cope somehow....:) I like the way it looks and how it transports me back to when I was a kid and saw a real Mk II in person right after LeMans. That has always been the high water mark for me.


Major components installed.


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Wow, 427SO and the ZF2! You have two very important things, without a doubt keep the project with the 427! If the goal is to maintain originality, don't hesitate, now if you want to press the accelerator regularly, it is important to see the condition of the block, otherwise it would be the best option to accept the advice of others here. I lean towards traditional as a tribute to this gem. The 4 main things that make the difference between the majority are the monocoque chassis made with detail and respect to the original, the pedal frame equal to the original, the 427 block and the ZF gearbox, with those 4 things a GT40 has his entire soul.
I’m in the early planning stages of my gt40 build. I spoke with Fran over at RCR and he said they can fit a 427 side oiler in their kit. My question is to people who have done it was there a ton of problems in doing it? I have a 427SO block and a ZF-2 box for it but I’m wondering if it’s worth the trouble of building it instead of a 351W or even a 302?

some questions are how hard it was to squeeze the engine in, access to work on engine, were you able to run AC, any regrets goingwith the big block?

thanks for any suggestions!

I will admit to liking the idea of a 427 side oiler if only for the following 2 reasons. The bore spacing and bore diameters are larger, so technically better internal geometry within the engine. It is also a deep skirted block so should be more ridged. Looks perfect in a MK II.

Down sides, weight, length, exhaust port angle, head and push rod interference with intake, old, complicated design with lots of different things that have been improved on with successive engine generations.

for Lemans they only ran them with 1 carburetor on them, so they were unstressed and more fuel efficient. Reports at the time quote 650Hp as the output. Winning Lemans has always been about fuel efficiency and staying out of the pits, not outright lap time. same still applies today.

"The Cobra Experience" museum has a number of the engines on display with a few other intakes set ups. Dual 4 barrels, 8 stack set ups and the like. If you are not going to fit the same intake set up and same cam and heads, is it going to be the same engine and give the same results? you could just as easily get the same or better driving experience from a built Cleavland or a Windsor, that would be more serviceable and have less compromises in the car.
I ended up saving the SO block and building a stroked out 363 instead. Will save a ton of space and weight and pulls 550hp with 8 stack setup. Now I just need to get a pulley system with accessories for the front end so I can get started in spring.
I ended up saving the SO block and building a stroked out 363 instead. Will save a ton of space and weight and pulls 550hp with 8 stack setup. Now I just need to get a pulley system with accessories for the front end so I can get started in spring.
I think that was the right choice! I have a 427 FE in my cobra too and in my view it is way too boisterous for the GT. As others said in earlier posts, just too much stress in the drivetrain. (A lot of fun in a cobra though). I've got a 302 in my recently completed GT, not mad, built with Edelbrock's 367 kit (which is probably nearer 300!) with big valve heads and KB high comp pistons, all nicely balanced. It's a very different driving experience to the cobra but fun in a different way! I missed the thump in the chest initially but am enjoying the difference now. Even with the smaller engine, wedging in accessories was a challenge in my car!
I am the new kid in the block ! Even if I am 66. I will present you my car in a few weeks, I bought an unfinished RCR GT40 with a DART engine based on a 302 but stroked to 347.
The reason I am anserving is because I know very well the 427. I built a 63 1/2 Galaxie with a 427 big block Tunnel Port (close to the Le Mans version) that I use on track days. My engine has every think inside to make a good engine and is giving about 520 hp at 6000rpm.

Even if you think this will create a version more conformed to the Le Mans car, you have to consider several desavantages, some were already mentionned; like the size. I wish to insist on the heat, this engine is generating a lot of heat, even in a big car like the Galaxie, you feel it, I cannot imagine what will happen in a GT40.
The second problem is the weight ; you will put 300lbs more in your car and may be only 100HP more compare to a small block. Of course the torque is gigantic, but do you need it for a light car like this ? Ford used some GT40 in Le Mans with an automatic transmission and only 2 gears. With the Galaxie on some race track I only use 2 gears on the 4 available because of the torque and the car weight 3700lbs. Your GT40 will loos the vivacity and you will never use the 5 speed. Regarding the gear box I thing the ZF will handle it, I use a standard 4 speeds top loader, but I do not know if the end ratio will handle the torque compare to a 9in with a Detroit Locker on the Galaxie. But you will need a reinforced clutch.
Another problem is the sensitivity to a good lubrification. Oil circuit needs to be optimized, and if you do not use the dry sump, I strongly suggest you put an Accusump because the lateral G obtained with the GT40 will kill the engine quickly.
I hope it helps !


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Mortified GT
I think it depends what you put it into. Mk1 would not be possible with height restrictions.

Mk2 if going into a monocoque for sure yes, but for a replica it all depends on if you see it viable to put a $60k+ engine into a replica which will not have any increase in value with a $60k or $6k engine. Also bolting a 427 Sideoiler to a ZF box, which would likely shed its cogs might not be very financially viable looking at ZF parts and rebuild costs.

But if I had one 427 sideoiler kicking about in my old shed, I would love to stick it in one of my builds, mono or replica just for the hell of it.

Do it how you want to build your GT.
These days, the 427 FE Alloy engines are far better and 45% lighter than the cast iron versions.
Not sure if you can make a side oiler out of any FE engine.

Shelby lists even complete alloy 427 FE crate engines.
I thought I would chime in on this subject. I recently got a SPF MKII and had a Shelby Engines 427FE installed in it along with a Quaife transaxle. I wanted a MKII as it was the first model to win Le Mans and I wanted the proper engine for it. It probably helps that my Cobra also has a 427FE - a 1960's vintage center oiler. I selected the Quaife as supposedly they are a bit stronger than the ZF/RBT - plus I had one available to me. Of course it's also important to get the revised Quaife following their rehash to fix the earlier problems. I can confirm the FE is a tight fit in the GT40 but it fits - even with AC. I had Dennis Olthoff install the engine/transaxle as I figured he would know what accessories, brackets, and other pieces to use to make everything fit. I'm not planning to race the car so I'm not too worried about the transaxle but I know there's a bit of risk. The sound is great and in 2nd/3rd gear on an onramp it pulls like a mad bull. I haven't had any problem with burning the Avon tires. It's easy to modulate the throttle to avoid unwanted excitement. As far as heat, I believe a 427FE in a MKII is probably cooler in the engine compartment than a MKI with a small block due to all the extra ventilation in the rear clip. I had a set of SS headers built for it and they have turned a nice gold color except up close to the heads where they have the more typical rainbow bluing due to the higher heat there. The car only has about 600 miles on it so far so I'm still getting it and myself sorted out. Overall I am very pleased with the package and so far wouldn't change anything.


Randy Folsom

I ended up saving the SO block and building a stroked out 363 instead. Will save a ton of space and weight and pulls 550hp with 8 stack setup. Now I just need to get a pulley system with accessories for the front end so I can get started in spring.
Pat, I am also looking at front runner options for my 302/363. My understanding is that CVF sells a kit that includes an A/C compressor mount. I was also told to use a stubby water pump with a V-belt to save space. I am considering using an electric water pump which would save even more space. Please let me know if you find something better than CVF. Cheers, Randy
Randy, if you go with the short mechanical pump (M-8501-E351S), you’ll need to buy the CVF single, double or triple groove pump pulley, depending on your requirements. The kits CVF sells for the short pump are single, double or triple groove, but you can’t mix and match between kits. You can however buy pulleys individually to suit your needs. I’ve just gone through this myself to correct what the PO had done. There’s a bit more to it regarding spacers and such, let me know if you have questions.
10'' from rear block face to centre of output shafts on T44. Cant recall what the same distance.
is on a ZF fitment.

Jim Craik

Lifetime Supporter
Keep in mind the 40 was designed for the small block motor, lighter, cooler, sounds better and won’t blister your paint.

Howard Jones

If I were building an MK2 version or even an MK4 I would be doing an aluminum block and heads FE-type engine and use a Porsche 930 4-speed transaxle. That's about as close to the original power train as you can get and still be in the weight range of an iron block/aluminum head 351W stroked 427. The 930 is a four-speed like the T44 and is stronger than a ZF. It's widely available and serviceable as far as vendors and parts. I also think it would be a lot less money than finding and buying a T44......if that's even really possible.

That's my story and I'm sticking to it.