I read the thread ending in 2009 about putting a 351 based motor in a Comet/Mav. Most opinions were somewhat to very negative. Maybe it is easier now than it was in 2009. I have this motor and want to put it in my Comet. It will be automatic and streetable but will see mostly track duty. Any and all comments and/or suggestions as to parts and issues/problems would be appreciated. I am hard headed and not easily swayed to abandon this desire. lol
If I ever do a Phase 3 on my car it would include a Mustang II type suspension, elimination of the shock towers and tower braces, and a 427 Windsor. Should be a torque monster and great fun. If you go ahead with it I hope you do a project thread.
To take advantage of the cubic inches you really need larger tube headers. That is where the car design gets in the way. Notch/shave the shock towers is the first choice. Mustang II or AJE Strut type front suspension would give you more room. Once this is accomplished your on your way. Not sure if you will find off the shelf headers with big enough tubes that will fit, but you can always build a set.
I had a 351W in my 71 Grabber when i bought it. The shock towers were not notched and everything fit under the hood, It was a pain to change the spark plugs. I would not do it again without at least notching the towers. Complete Mustang ll suspension would be my first choice.
My Maverick has a 351w with TF-R heads..................and my towers are shaved. The car was a B/SM back in the late 70's/early 80's and had a Boss 302 without shaving the towers. There is one other person on this site running a Boss 302 that has stock towers. Now with that said I basically have to take my headers off (at least tubes for cylinders 4, 7, and 8) to change the plugs.........and at the track it's difficult to look at the plugs or change them with hot headers. So, if you have your mind set................you will almost have to build your own headers. As for the tube size, it just depends on your motor. Mine has stepped headers, 1-3/4" Primary and 1-7/8 Secondary...........about 32" long with 13degree merge collectors and 3"Megaphone..........the engine is a 408ci and spun the dyno to 640hp @ 6800...........so, you don't need huge headers......just well designed ones. Other than the header issue, there is not much to it. I run a Powerglide but my car is drag only.............no street duty since it has a spool and no exhaust..........................plus the 4/5 miles per gallon on 114 is just not in my budget. I wish I didn't have the shock towers................because that would make the swap a piece of cake..........................IMHO
I have a healthy 351 with an AOD and headers in my Sprint...Granted its tight...But I wouldnt say the lack of space is a deal breaker. As for headers...Best bet...Fab your own, Nothing really fits without modification. I can change the plugs in my Sprint in 20 minutes with the engine cold...You do have to pop it off the mounts but, its only 2 bolts and a jack...Not a big deal. Hood clearance is another issue...If you plan to run a tall intake like an airgap or something to that effect. You will not have adequate hood clearance. But...Thats what scoops are for. Stock 302 motor mounts work...302 accessories work...If the tranny was bolted to a 302...It will bolt to the 351 etc...Its all the same architecture between the 302 and 351...The 351s' deck height is what makes it all difficult to do. I say go for it...The low RPM torque makes it worth while with a mild 351...A stroker...LOL... Just make sure you use good parts for the drivetrain and the brakes...
My 351w fit without shaving the towers, at least not in the traditional way. My clearance problems were lower on the tower. I had to notch and box in part of the area between the mounts and the tower, plus cut down and flatten out the vertical "hump" in the middle of the lower part of the tower. Then the upper control arm nuts/studs were in the way. "Shelby drop" took care of that. When it's all together you can't see those mods, nor can you really even see the headers. Now, the headers I used do have 1.5" primaries. They could certainly stand to be bigger, but then I think it would be even tougher to fit them if they were. I'm sure I had the engine in and out of the car ten times before they fit, even with these smaller tubes. I think they're enough for my build. (GT40 heads only have 1.54" exhaust valves anyway, can't be that much of a restriction.) But maybe not someone else's... As for hood clearance, my intake is a Ford Motorsport manifold that was cast by Edelbrock and is identical to a Performer RPM. As you can see in the pic, I've got a stock type breather in there with room to spare. Your mileage may vary though.
427 into a COMET Been reading your entries: I put a 427 MAN-O-WAR block withAFR heads,fuel injection,Lentech AOD tranny and the rest. I removed the shock towers and put in different rack and pinion steering .. along with all the other necessary components. With more HP there is always more HEAT .. so I updated the Radiator , twin elec.fans , tranny cooler with fans etc.etc. It was a change that was somewhat difficult but more than worth the effort . I can truly recommend it just for the "Grin-Factor" I'm presently installing a stroked 408 bumping 525 HP into another Comet with the same front end work , Shock Towers Removed, but this one has a carb and a 5-Speed Tremec with a 3.25 9 inch posi and roll cage. I wish you success with your project. Cometized
427 in a Comet I am thinking the smart thing to do is what you suggest and remove the shock towers if I do the 427. It will drive better with new suspension. My car is a very nice GT (but is already modified quite a bit). Accordingly, I have reservations about "cutting" the car. Don't know how much it will hurt the value and desirability should I decide to sell it. Enough whining...lol What header do you recommend. This is an AFR 205 hyd roller motor. Am expecting it to be in the 575 hp range. Probably need 1 7/8" primaries. Thx Rod
Just cut the shock towers out, if it's done properly, it'll increase the value of the car, if you ever sell it.