I am considering the different aluminum heads that I can make FIT on my stock block 351M that is in my 1979 Ranchero. Most anything I do to it will increase HP, so I am no overly concerned with that part, what I do want is torque to move my 4000lb daily driver. I have considered the Edelbrock 61629 heads as the would be an easy solution for increased efficiency, improved combustion chamber design, and higher compression. I don't like the idea of spending $1,800.00 on a $500.00 driver. HAHA.
Has anyone considered other aftermarket aluminum heads on their 351M. I can buy them for $700.00 and I would need to make custom spacers for the intake and plumb the heads for a water crossover, not too big of a deal and I could probably get it done for less than $1,100.00. This would give me the bump up in compression, have smaller ports for good low rpm velocity and aluminum construction. I do understand that beyond the custom spacers and crossover, I would need custom length pushrods and small block headers to fit the exhaust port. Am I missing anything else here? I am not overly concerned with high flow numbers as the motor rarely sees anything above 5,000 rpm. I don't need the extra cubes of a 400 either. Just a very efficient motor that I can drive every day. Thanks!!

 

The 351m just isn't going to be easy. Spending the money your talking is going to be a big disappointment.

Your problem is, of course, low compression & a crappy cam. Not so much the amount the heads will flow. (does it ever get over 3500 rpm?)

SO...the "quick fix" might be a straight up timing set, if you don't have one already. A good dual or large capacity single exhaust.

Next up would be a dual plane 4bbl manifold and small 4bbl.

A cam swap will make a world of difference, as the stock cams are reviled, and cam technology has marched quite a distance since that motor was turned out.

351M/400 Performance Build Up

M-Block 351M/400 Parts Reference

Manifolds:

Edelbrock.com - Manifolds - Ford - Small-Block - Performer RPM - 351C/351M/400M

Cam:

266 H10 camshaft - Fd. 351C- 351M- 400 V8 70- 82

All items serving suggestion, ymmv.

FWIW, the conversion to a 400 along with the improved compression and the cam/manifolds etc, would give you effortless power with no worse mpgs than you get now, or so goes the tale....

Good luck with it, but don't buy heads and expect a miracle....

 

I have already put in a straight up timing chain and gear set and re-curved the stock duraspark distributor. I have a set of headers and dual exhaust waiting for a long weekend to install. I also have a 600 Edelbrock, but I am really looking for a 500, and have an old Offenhauser dual port intake that I'm going to give a shot, I also have a performer intake if the dual port doesn't work out. I get solid 18mpg on the highway and 15 in town, usually with 500 lbs of tools and junk in the back. I know some guys that are making $400.00 per mo. truck payments would love to get that kind of mileage, but I want to get solid into the 20's. It is a good driver and performance is strong for what it is. I also have set of 1.8 roller rockers a that I had acquired to bump up the stock cam, with out changing springs. That was before I started exploring the aluminum heads on the market. Also considering MSD or other ignition components. Again efficiency and mileage are my biggest concern as I know the items listed above and by 85e150 will boost HP. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>
My newest thought of going to Windsor type heads made me think and so my original question. To build an efficient, inexpensive, torque motor. Would a set of aftermarket Windsor heads go along with the rest of the package, other than different headers and spacers mentioned in the op. <o></o>
Has anyone else tried this? <o></o>
It looks like the advantages would be:<o></o>
increased compression<o></o>
improved combustion chamber<o></o>
increased port velocity <o></o>
lighter weight<o></o>
all without touching the shortblock?? Just a thought, what do you think. Thanks,<o></o>
Yea, $1800 for heads would be a miracle, but the $700 may be do-able...<o></o>
<o></o>

 

ignitions upgrade definetly. also a better tunable carb vacume secondary. edelbrock are OK but their is better out their. Been running quickfuels for awhile now and really like. they have a excellent tech page to read on for fine tuning your engine. the metering plates have lots of potential for tuning and getting that optimum tune at all your rpm requirements. read an learn about annular boosters for low rpm requirements. on the heads i wouldn't mess with learn on how to fine tune what you have. yes a better combustion chamber would be nice but for what you are doing i don't think it will do what you want. bang for the buck situation. what tranny you have. if auto torque converter is a big deal. Check into hughes performance torque converters for mileage. the have some nice stuff. catch you later. do you have a air fuel tester for tuning??

 

Thanks guys, I appreciate the input.
Wyoming,
The tune is pretty decent, starts and runs better than many fuel injection vehicles. I do not have a air fuel tester, I use mostly old school equipment for tuning. Vacuum gauge, timing light, tach, reading plugs ect…
Do you feel the druaspark is not supplying enough ignition for an 8:1 motor that does not see much over 4500 rpm? I am looking at a coil and maybe a MSD, but a proper functioning and tuned duraspark seems to do a decent job. I looked at the QF, it looks like the ultra adjustable Holley which would be good getting down to a fine tune, but also a fine tune one day, is not a fine tune another day as the weather changes.
Right now it has the stock FMX trans, but I am seriously looking at a close ratio ZF5

 

I believe any modern ignition with multistrike capabilities is a upgrade. the msd 6 is a good start. MSD multiple spark distributor. I've been running MSD for years and very reliable. their are others out their but MSD is still the standard in ignitions. MSD is multistrike up to 3000rpm's. If you can get a small air fuel tester would help you fine tune your application. One thing i do know with engines is the best engines out their don't always win but usually the best tuned. On the tranny check into hughesperformance trannys. check into their site on mileage converters. i'm a big fan of auto's and some of the modern torque converters out their. if wanting to spend some money check into innovate on some of their handheld air fuel testers and FAST has some nice pieces for in cab monitoring of Air fuel. I believe these tools will help you possibly get a little better tune or confirm what you are doing. sounds like your doing a excellent job as it is. catch you later and will check in later.

 

For the cost of the after market spacers etc and having to muck around plumbing up the water jacket, sounds a pain. the mod you are suggesting is usually done the other way around with cleveland heads on the windsor. How much to get a set of 302 aussie heads? that is the other way (not alloy though) to raise the compression and they are relatively thick on the ground here in Aussie (of course LOL) and not that pricey. The headers and exhaust would be the first thing to do. They wouldn't be in the way too much if you had to swap the heads later and you already have them. I have rebuilt my 400 and while it has a nice note with a dual system it is still running the original cast log jobbies, which are about to fall apart by the way so I will have to shoe horn them in soon!
There is an article in a hot rod magazine I had somewhere (online) that rebuilt the engine with ported cast manifolds and the original 2bbl manifold with a holley 500 on it and they were very happy. The air velocity from the smaller ports both side of the bang really helped with torque. It was a 400 though but I suppose the logic is the same. The other way to go would be to reuse your heads and get a 400 rotating assembly. it may even fit in your budget, but then you are rebuilding the engine anyway so that is another thing together.!!

 

Crsmiffy.
I can make the spacers, if I can find someone around here in NE Indiana that would give me access to a mill. I just moved and am still new to the area. I enjoy machine work and I think it may be a worthwhile project. I know it is usually done the other way around and that is what makes it fun to contemplate. I am going to continue with the headers, exhaust, intake, carb. and roller rockers. But the whole reverse head swap is intriguing. I want to stay with the small displacement, all things being equal, it will use less fuel. Also looking at a ZF5 to replace the FMX.

 

Fair call. Back in the day when I was a fitter/turner (read machinist) and I had access to the gear I would probably consider the same, although fun v cost can be an interesting thing LOL. Don't know if going to a lower ratio roller rocker is going to do you any favours as you would lose valve lift. May work with the rest of the build though. The ZF5 is a manual? you are very lucky to have the 351m block that takes the FMX.

 

I’ve got 1.8 rockers, will give me a little more lift over the factory stamped 1.73 rockers, plus the rollers may free up a little friction hp. The ZF5 trans is a manual 5 speed used in ¾ and 1 ton trucks, Its kinda heavy by today’s standards, but lighter than the old FMX in now have. Thanks for your input.

 

Ha got the ratio around the wrong way. Sorry. You could go the AOD with the small block pattern. Then you could have the taller ratio and an auto.

 

He would need an expensive adaptor for the AOD. His motor is the 385 series pattern, not SBF.

As for the ZF in a Ranchero--do you need a granny first?

A T5 would give you tighter ratios and a taller 5th--depending on your axle ratio, that might work more better....

 

if he has one of these it should be a "small block" 335 series pattern-these are like unicorn excrement

Good Advice on the manual tranny.

 

manual tranny issues with zf-47. the big block tranny ZF to 351m is not a bolt in situation. the input shaft is to short. Have to build a longer pilot bushing about 1" instead of 1/2". the input shaft barely extends into standard pilot bushing. what I haven't checked into is the starter alignment to flywheel situation. slave cylinder is different also. it can be done but not a bolt in situation to a 351m/400.

 

zf-42 is for 4wd and the zf-47 is 2wd. the 42 represents the torque rating 420 ftlb torque. 47 is 470ft lb torque. done some reading and these trannys and the later yrs are the better trannys after 1993 if I remember correctly. also getting clutch can be kinda tricky if wanting a 12 clutch. 351m is a standard 11" clutch. need to do some reading to get up to speed on this application. this tranny might cause some fitting issues because is built different at bellhousing. probably will rub firewall compared to factory application. its just thicker set up compared to the standard bellhousing. good luck. forgot to mention the shaft is bigger than the small block pattern. bigblock is 1.250 shaft and the smallblock is 1 1/16" shaft. things you need to know.