ok i have a 1984 f150 i put in a 1971-73 351 engine i kept the oringinal automatic trans in the truck the truck always cranked hard(like the starter and flexplate wasnt exactly true) the flexplate finally went out and i replaced the flexplate the trouble i have now is the starter and flexplate doesnt mesh correct ive tried different starters, ive tried shimming the starters out i took it to a mechcanic and he put on a 73 starter which seemed to work for about a week then the same thing, i bought a brand new starter and it worked for about a week now when you hit the key the starter just spins and doesnt engage the flexplate im thinking im going to have to junk the truck which i hate because i was fixing it up for my son dont no what else to do if any body has any ideas please let me know thankyou

 

Where did the flexplate come from? Maybe its not to spec, theres a lot of poor quality parts out there

 

You either have the wrong flexplate and/or the wrong starter. You installed a 351 (C or W?) from a Passenger Car and may be unaware that the starter used with an A/T is different than with a M/T.

1971/73: There are THREE possible 351 Passenger Car flexplates. What did the engine come from, is it a C (8 valve cover bolts) or a W (6 valve cover bolts)?

 

i have the flexplate for the 84 ford , i thought i had to match the flexplate with the transmission

 

m sorry its a windsor motor 6 bolts

 

Now...what make/model of car did it come from? You may not be able to use the flexplate from the 1984. One flexplate from 1971/73 is the same, the others are not.

And if you mis-match the flexplate with the harmonic balancer, you'll have a vibration that...sooner or later...will cause the center of the flexplate to tear out.

The flexplate has to match the harmonic balancer. Otherwise...

 

i bought the long block off of craigs list the previous owners said that they bought it for there 71 mustang and decided to go with another engine, the block is supposed to be brand new when i purchased it, i just put on the 84 flywheel and harmonic balancer

 

Pull out your starter, locate the block stamp(hidden by the starter) and post it up.

 

ok the numbers are p-47e-6c15-aa 7

 

Makes no sense. Block casting numbers are similar to this for a 351W of this vintage:

D1AE-6059-AA

What y'all are gonna do with this number I dunno, because block castings numbers cannot be cross referenced to Ford part numbers, and usually do not ID the engine size, or what vehicle it's from.

All (for example) D1AE sez is the block was cast in 1971...and that's it, cuz the same block was used in myriad Passenger Cars.

351W introduced in 1969 Passenger Cars, first installed in Econolines: 1975, F150/350's & Bronco's: 1980.

 

At least figure out what year the motor is

 

Cannot go by that either. The same D1AE block coulda also be used in 1972, maybe even 1973.

And since Ford casts blocks for service part replacements, and for use by Ford authorized engine rebuilders, the date code it was cast with could be years after the fact.

People go ga-ga over block casting numbers, but the fact is, most are worthless for ID'ing anything as they are strictly foundry marks.

 

I have a 84 F-150, 351 had starter problems for a year. Put a new flywheel on it and everything I could think of. I bought starters form advance, auto zone and others. I even bought there top of the line starters. Still no help would work maybe a day or maybe a month. So went to Napa one day just to see if there starter was any better. The manger there knew i had been having problems so he took the time to do a little research his self and found a starter that was 10 tooth. All the starters you buy at the local parts houses, even napa are 9 tooth to apply to more applications. So we ordered the 10 tooth, took a few days to get here. Put it on and I have not had a problem since.

 

do you happen to no which year the ten tooth starter is the parts guys can only find 9 tooth starters. Also do you know the number of the parts store manager you spoke to to get the starter. No one here can locate one and I am at my wits ends.

 

Did you install the factory shim plate that goes in between the motor and trans when you did your swap?