1979 f100 302 c/6 ordered that way from the factory.

replacing it with a 1980 302 that i bought (didn't fully break down the casting number but the D0 dates it to 1980 which jibes with the receipts). engine has machine shop receipts with lots of details but missing some key information apparently. no cam specs, didn't replace the crank, just fixed the old one but no details on it, cleaned two sets of heads and worked up one set but i don't know anything about them, edelbrock performer 4 bbl intake and now it has a 4 bbl edelbrock carb. lots more details on the receipts but i don't know if any of them are important at this point.

dropped it in, bolted it up, it had no flexplate or flywheel on it because it was going in front of a manual transmission and i don't know why it didn't have one but whatever. the distributor in it was points, the oil stick was in the side of the pan and falling out and siliconed in so i changed the pan to my truck pan and the timing cover and water pump to the one off my 79 motor to relocated the oil dipstick becuz mine's in the timing cover and still tight. in doing all that, we pulled the harmonic balancer and put the one off the 79 on it, and the flexplate off the 79 on it because i read that they're externally balanced and not fully understanding at the time, thought that well they worked together so they'll work. i'm also on a limited budget and well, didn't wanna buy a new flexplate unless i had to. apparently, wrong answer. i put my distributor in it which isn't points. we pulled the cap, looked at the position of the rotor and placed the other one in it as close to the same direction as possible (wouldn't go exactly straight forward but just a little bit off either side so i guess we picked the wrong tooth or something) while the pan etc was off so we cld turn that dumb oil pump drive shaft and make stabbing it easier. the PO had already pulled the plugs before we got there so we cld look in the holes at the piston heads so i cldn't tell you what the firing order was before we did this even if i would have thought to look, which i wldn't have honestly. apparently bad idea. the PO gave me a holley 4 bbl to rebuild and put on, it doesn't have a choke butterfly and apparently you can't buy those so i bought an adapter and put my motorcraft 2 bbl on it. again, bad idea. i'm pretty full of those if you haven't noticed.

i get to the point where i've got the carb on, the firing order checked and double checked, everything hooked up i think and ready to go and i can't get it to start much less get it in time. long story short, i take it to a mechanic because i'm frustrated after three weeks, frozen toes, and hundreds of miles going back and forth from where i work and where the tools and truck are, and he tells me first day he has it that it's got a 351 or a 302 HO cam in it becuz it's got the 351 firing order, hence why i can't get it timed cuz i'm using the 302 firing order..... IS THAT POSSIBLE??? that and i somehow managed to get it 180 off.... oh, and my carb adapter's broken and she's sucking too much air to run long enough to get it all timed right. so i go and buy an edelbrock 4 bbl carb and send it with my mom down to him. that's day one at the shop.

today he comes back and tells me he's got it running but there's exhaust coming out of a hole in the back of each head that's supposed to have something attached there (i can't remember what it was he said but if you know i'd really like to know) and so now since it's got a bolt hole beside each of those holes he's going to block it off. other than that he says it's got a vibration to it because i've got the wrong flexplate on it. i explained what i did and why and after asking me what year it is etc i ask him if he cld tell which flexplate it's supposed to have based on the old harmonic balancer that was on the engine when i got it. he said he couldn't and while most people say there are only 2 different ones, there's really like 4 and that i should drive it around, and when i said to see if it smooths out he didn't disagree with me. this call happened while i was at work and i was trying not to be distracted he's not much for conversation anyway and who cld blame him talking to me who doesn't know my butt from a hole in the ground apparently.

so now i've got an engine that is apparently going to be pretty hot if i ever get it right, i don't know what those holes in the back of the heads are supposed to go to, i don't know what the repercussions to blocking them off will be, i don't know if it's even possible to have a 351 cam in the thing or how i cld have the 351 firing order on a 302 w/o knowing if the crank was changed which wld help me find out which stupid flexplate/balancer combo i'm supposed to have, i don't know a whole heck of a lot and i'm about to pull my hair out.

so now knowing the short version of what i know, is there any hope to finding out what flexplate i'm supposed to have because, thought i probably shouldn't, i'm assuming that the balancer that was on it was the right one because supposedly, the story of how this engine came to me goes like this. man in the rich part of town restores an old mustang, has this engine built for that, gets it and gets it in, drives it two days, wrecks it, pulls it, stores it for 3 years, sells it to the guy i bought it from who got it for his mustang project, kept it stored inside until i bought it this year. the machine work was done in 99 per the receipts and the story. i don't know if it was in front of a manual transmission in that mustang or not but i do know that the bill of sale from guy #1 to guy #2 says no driven miles on it thought guy #2 told me the dude drove it for a couple days. *shrug*

Any and all help is appreciated because i'm so lost i don't know even where to start!

 

I can't tell you what flexplate the motor should have but I can explain the cam and the holes in the heads. The holes are for an air injection system that is supposed to be used in conjunction with a catalytic converter, if you don have this just block them off. These holes may be threaded and a standard pipe thread plug will fit if they are.
All mustangs and 351 motors got the same firing order, 13726548, and the cam is what determines the firing order. You can put a cam with the 15426378 firing order in either of these engines and it will run as well.

 

I got lost after the first paragraph/sentence.

 

ok according to everything i have the 15426378 is the firing order for a 302 and the mechanic said this one has the 351 order which i'm assuming is the 13726548 that you mentioned. he said it's either a 302 HO cam which is a cop car package or a 351 cam. *shrug* but does the crank have to be a special one to make it work? and if so, that means i wld need the correct flexplate and balancer for that crank rather than the stock 1980 crank which apparently needed the 50 oz and if i remember what i read correctly the 1979 302 that i pulled out wld have used the 28 oz which wld have been what i put on because i didn't have a clue. (i might have those two numbers backwards btw, my brain's not functioning properly right now)

so basically, i think my best bet is to hope that i'm not making a HUGE mistake assuming the balancer that was on it before i changed them is the correct balance for the stupid thing and try to match a flexplate to that to get it all copacetic... is there anyway someone cld test to see which one it needs or is it a knowledge kinda you know this information so you know it needs this part type situation? i asked him if he wld know which flexplate it needs if he were to have the balancer that i took off of it and he said he wldn't...

???

 

Any 302 can use the 351W firing order, that's dependent on the cam used, not the crank. Same crank for all as far as firing order is concerned. The 85-95 H.O. 5.0 wasn't the only use of the 351W firing order in 5.0's. All 94-97 pickups and vans used this order with their F4TE roller cam. And all the 96-2001 Explorer/Mountaineer 5.0's did as well (same F4TE cam in these too).If it turns out that the cam is the F4TE, then you're in luck there too. This cam is an EFI grind but works fantastically with a carb. Now, if your engine still shakes after you've fixed the vacuum leaks and gotten the firing order correct, then you need to look at the balancer and flexplate/flywheel as being the wrong ones for it. Ford changed the imbalance factor on the 5.0 cranks somewhere in 1981-1982. If you can remove the oilpan to see the crank, you can then get the crank casting numbers to see what crank it is. The 2MA crank is a 50 oz/in crank. A 2M is a 28 oz/in.These numbers are usually found on the second counterweight from the front. You can also possibly tell which it is by looking at the rear seal. If it has a one piece rear seal, it's a 50 oz crank.

 

i wish i had known to do that when i had the pan off and it was hanging from a chain hoist! i was writing down every number i saw and my dad said quite worrying about the numbers and get over here and do this or that or the other....

surely the mechanic i'm using (a self professed 302 nut) is smart enough to check for vaccuum leaks... you would think.... but i'll look at all the lines that i know where are tmw.

i don't know if i can get casting numbers or a look at the rear seal now but i'll see what i can find out. if i knew which one i had on it right now, then i cld take a stab in the dark and get the other one to put on it and see if that works with the original balancer that i still have sitting by the old motor...

so was i right that the 28 oz came first and they changed to the 50 oz later or did i have that backwards? also, i think i read somewhere that they have a different amount of teeth on them so if i count the teeth on the dumb thing (i have an old one that we had changed when i had a starter chewing problem that would have had to be the same size they put back on) then maybe that could tell me which i've got on it right now and just go with the other one?

and he also said that most people only know about the two different weights but that there are really like 4 or 5... ??? anyone know anything about that?

 

To check for vacuum leaks, take a can of spray carb cleaner and while the engine is running, spray all around the top of the motor and see if the idle changes. If it does, you can isolate the leak with the carb cleaner. When the cleaner hits the leak, the idle will tell you. As for the balancer, you can try that too. When it comes to flywheels and flexplates, there were 3 different sized flexplates for a 302 (auto trans) these usually are refered to by the tooth count on the ring gear---147 (Mustang II only) 157 (most midsize cars) and 164 (this was mostly used on the larger cars, trucks and 351W & 351C) The 164 is the only one that came in two balance weights--28 & 50 (you can buy an aftermarket 157 tooth 50 oz flexplate though) You're correct the 28 came first. In flywheels, there were just two sizes--157 & 164, in both balance weights each. Trucks usually got the 164 tooth. The 157 tooth 50 oz was for the Mustang & Capri's manual trans. 28 & 50 are the only two balance weights ever used.

 

Seeing that you're in Lubbock, there's a couple of Mustang guys that hang out on StangNet.com's classic forums that could possibly help you out. One is "bnickel" and the other is "jikelly" both live in Lubbock too.

 

Ever read the "So I went to see the custom engine builder" thread? This guy spent a lot more money than you to have the same problem. I think almost everyone does the 180 deg thing at least once in their life. Don't give up, you're almost done!

 

wouldn't it be funny if one of those guys ended up being the original owner that had this thing built in 99. that'd be a kick in the pants wouldn't it.

i was told today that i just need to get the flexplate for a 302 ho motor which of course doesn't tell me much. being that it's a 1980 i'm guessing 50 oz.

if i'm wrapping my brain around this correctly baddad, i should need a 164 tooth 50 oz flexplate because i've got the truck starter on it and that's what the teeth need to match too correct? Do these things actually weigh 50 ounces where i cld weigh the thing and tell what i've got?? that'd be just a whole heck of a lot simpler to accomplish... take my old one up there (assuming it's a 28 oz) hold one in each hand and get the one i don't have already. i'm going to go idle her the five miles back to my parents tonight and i can bring my old busted toothed one up here and buy the parts and do this over christmas while i have four days...

Y'all have been a wonderful help!!!!!!!

 

Depends on what transmission you have in there as to flexplate size. The 28 & 50 refers to the "imbalance factor" that the factory used to correct the dynamic balancing requirements of the crank and rotating assembly (rods, pistons, rings and crank) Actually the correct term is 28 ounces per inch or 50 onces per inch. As to the actaul weight of the counterweight, that you'd have to ask a person that does engine balancing or remove the weight from a flexplate and weigh it. The weight you'd have would only be correct for that flexplate size, a 28 oz weight is different for a 157 as opposed to a 164 tooth plate. and the same thing applies to a 157 & 164 tooth 50 oz as well. Your 79 could have one of three different automatics in it. These are a C-4, C-6 or an FMX. Only the C-4 could have either 157 or 164 tooth flexplates, depends on which bellhousing's on it. Both the C-6 and FMX used 164 tooth plates only. Same one for both I think. If it's got an AOD, it'll need a 164 tooth same for a C-5 if by chance it's got that one. The C-4 is all aluminum (bell, main case & tail housing) with a removeable bell. The oilpan is square. The C-6 is also all aluminum, but the bellhousing is one with the main case, the pan has a notch in the right rear corner. The FMX has an aluminum bell, cast iron case and aluminum tailhousing. Oilpan is rectangular with the longsides toward the back and front. The AOD will have the words "Metric" stamped into the oilpan and is all aluminum with an integral bell. The C-5 looks like a C-4 and basically is, but had a lockup converter and a deeper bellhousing for this converter.

 

i've got a c6 that bolts to a 302. i believe that requires a different bellhousing because of the bolt pattern.... either way, i think since it's a 79 i prolly have the 164 tooth 28 oz. so should i try the 50 oz 164 tooth or is there something completely different for 302 HO?

 

LOL I'm glad I'm not the only one.

 

All 302's had the same bellhousing bolt pattern. C-6's came in three patterns, small block, FE big block and the 351M/400/429/460 big block pattern. If the 164 tooth 28 oz flex works but it shakes, the only other choice is a 164 tooth 50 oz flex. If you need one of these I have a half dozen extras, you pay the shipping and I'll send you a couple.

 

IMO, pull the pan, and get the crank number. the flywheel, crank (and harmonic balancer) want to match each other. So if the builder put a newer than 1981 crankshaft in there, you want the 50 oz. imbalance. 1980 and older, you want the 28 oz. imbalance. Doesn't matter what the block is, just the crank. IIRC, the block's casting number hasn't changed since 1970 IE D0ae. for kicks, see if it says D0Ze.