Originally when I started to look for a body for a 429/460 engine I pretty soon realized that the ’71-’73 Mustang has one of the widest enginebay of unibody Fords and as mentioned above they were factory option 429 as Thunder Jet, Cobra Jet and Super Cobra Jet versions. That’s why I wanted for a ’71-’73 Mach. Once I found the body, I drove 50 miles with the 351c 4V, yank it up, sold it, bought a brand spanking new Ford Racing 460 cid from Friendsville Tennesee.
I did used the original 351c framemounts and OEM 429 enginemounts. Now thinking the engine sits probably little bit of higher than with the correct 429 frame mounts. If I would be now starting the swap I would do the swap with the readily available frame & enginemounts from MU.
What comes for your questions.
1) There are no issues with the factory hood with anything else than Victor Jr, Weiand Stealth and tunnelram’s. Victor Jr will fit but you must use very low aircleaner, Stealth is little bit lower than Vic Jr. I needed to cut the hood due to 4” aircleanerelement, 2” spacer, without the spacer and with lower profile aircleaner with Victor Jr you can go with stock Ram-Air hood without cutting the hood.
2) Valvecover & power brake booster clearance. Even with the tall 4 ½” Ford Racing covers there will be 1” or so clearance. No problem. If you go with lower profile covers the clearance gets bigger. There are several diffrent valvecover from Summit racing you can find 19 diffrent covers and then there are other manufactures that does not list at Summit like Blue Thunder Auto.
3) Changing spark plugs can be done without yanking the engine up. Plugwires you will need to remove though… I’ll use this kind of tool to open and to tightening the plugs – no issues at all:
http://www.summitracing.com/parts/wmr-w1129c/overview/
I mentioned earlier that it’ll take 45-60 minutes to change the plugs, plugs out, adjust the new caps and threw the new ones in that’s not breaking the sweat. You can do it faster.
4) Accessories, I did used 351c powersteering pump, alternator in the beginning, but ofcourse all the brackets are the 429/460 specific. I have now aluminium alternator brackets and the 429 montego power steering bracket. Now I have Volvo’s alternator and newer Ford plastic & aluminum power steering pump.
5) IMO your though of using the Ford Power Train Application headers is the best way to shoot for the streets. They’ll support very high hp rates and they are high quality headers with incredible fitment and huge ground clearance. If I would be now buying headers I wouldn’t hesitate to contact Ford Power Train.
6) If you want to go with the 429 Hooker Super Competition 2 1/8” primary headers you’ll bump in to oilfilter fitment issue, filter will be touching the #5 primary tube. Not good thing, so then you’ll need to get an adjustable leg (ford racing has them M-6880-A50) or go for remote oil filter location – makes easier to change the filter though… No fitment issues with FPT headers, this only the big 2 1/8” header problem. Big supercomps also needs to cut a hole to inner fender to the passengers side and remove one bracket from inside the fender.
7) To do. I would try to find 429/460 out of Cougar, Cyclone, Montego or which got all the bracketry. That way you would have all the necessary parts without the hassle or the joy of mocking them up.
8) To do. Buy a big radiator, the ’71-’73 enginebay is huge, it’ll swallow a massive radiator. Or just get a 429 comparable radiator. Use shroud.
To be honest an extra cost that may appear comes from the powertrain, since you can make fairly cheap a strong 429/460 cid engine, they’ll produce so much torque & hp that you may want to start upgrading your powertrain. With similar output 351w/351c you would also need to upgrade the powertrain anyway.
MPG. Whatever the engine is with f.ex. 500hp/500lb-ft will take some gasoline no matter how the power is done if the power is used. Prius 1.4 liter ecohydromaxboosthugatree with 500 hp is not a MPG monster. Making a n/a horsepower will need gasoline that’s for sure = power doesn’t came for free. My '72 Mach 1 with +580hp with 550 lb-ft of torque (I found the the dynochart) 460cid std stroke&bore, hydraulic flat tappet cam 244 in 254 ex 0.588” in and 0.614” exh = fairly stout hyd.flat.tappet , 4.11 gears with 28" tall rear tires 275/60-15 and manual TKO600 0,64 fifth gear. With this combination it is app. 2000 rpm on 60 mph. With 2000 rpm the big engine produces nice torque, you can overtake safely just by pressing the pedal on fifth gear and the engine just pulls away. If you change to third gear the rpm will raise from the 2000 rpm to 4000 and be carefull if you hit the pedal, it can still break the rear tires loose (don’t ask how I know - ooops).
I made it 14.7 MPG on highway with some hammering (120mph with fourth gear and few smoky lift offs - yet most of the time 60 mph and I still felt that the carb wasn't as tuned as it could be. In a traffic, idling in the city etc will make the MPG worst naturally but so it does with any engine.
Here are few pictures from my enginebay. I have 2 Flex-a-lite puller fans, March performance aluminium pulleys – no A/C here. Finnish summer is so short that no need for one… There’s a ¼” spacer between the waterpump pulley and waterpump’s flange, my alternator, powersteering were all lined up nicely but the waterpump was out of line for the v-belt, so it sticks little bit of further. Still I’ve got enough room for the fans placed between the engine and the radiator. By using the 429 specific parts you cannot go wrong, since they’ve been designed by the factory.
Here you can see the space between passenger shocktower, plenty of room to change the plugs. I even took the heads off with the cylinder head studs on the block, passenger side just popped off and on the drivers side I loosened up the masterbrake cylinder bolts and carefully bended the cylinder a little and the head came off.
Here’s the space between pulleys and fans.
There are few goodies you get too with 429/460 engines. Make it 500 hp. You don’t need to search for high nodular big $$$ block, just get any 460 block or 429 block you can find, it can take 0.080” overbore (4.440”) without a sonic check, my friends Ford OEM 460 block was bored straight to 4.500” after it was sonic checked – now that’s not bad from an original Ford block. 429/460 does not need hard fill anything under 800 hp, at 800 hp it starts to see cap walk. Then it is time to make the block for 4-bolt mains, there’s enough material to do it without effecting to the rigidity of the block. All the marine 460 engines has the marine rods - A75 , they’re upgraded Cobra Jet connection rods, just get ARP bolts and you’re good to go. Crankcase can take 4.500” stroke crank, that combined to 0.080” over makes 4.440” bore and overall cid goes to massive 557 cid wit Ford OEM block. Look for a D9TE block so you can get already a 0.200” longer cylinders, they’ll support the long stroke engine pistons better, so it’s good block for stroker cranks and it is very common block, D9TE block was made from 1979 – 1997. Aftermarket blocks are available also and can be bored from 4.360” to 4.700” and they hp-ratings start from 1500 hp.
So aftermath, you can get very good bang for the buck to 500 hp / +500 lb-ft range with 429/460 cid. I guarantee that after few hundred miles you’re already thinking of getting more hp & torque. At that point, you’ve got all the aces left, stroke it, cam it, give it good set of heads like Jon Kaase P-51 heads and you’ve got there a big engine with good manners due to huge displacement.
Sorry for the long post... :blush: