help thanks

ok got a 302 cobra engine that was bilt buy twister engines for a 67 shelby cobra, but is now in my 90 mustang, with a 650 carb, and a t5 trans, when i drive and go above like 2500rpm the hole engine and car shakes pritty bad, i have bbk headers and x pipe with flowmasters mufflers, tublar k member and a arms with polyuthane motor mounts and trans mounts, kyb front struts with bbk coil overs and caster camber plates, msd intion and coil, some what new clutch not sure on the brands tho. when i put the clutch in i did not have a clutch alinment tool so i eye balled it and it shook really really really bad so i took it to a shop to get it alighned just because i did not want to do it, but it still shakes pritty bad, could it be a head gasket or some other gasket i am leaking oil in back of the intake manifold but not alot, thanks alot.

You have drivetrain issues and its not a gasket. You sure your motor is balanced?

yeah it came right out of a 67 cobra, so it had to, also would it matter that the trans is not totally sealed like i dont have my spedo cable in yet, i just have the hole covered enough so that it only drips a little trans fluid for now till i can get the stupid spedo thing i through away, lol

Do a compression check. Check the balancer. Check to see if the flywheel is cracked. Try putting the car up on jackstands and put it in gear while running to make the tires spin. See if you can locate the problem this way. But dont do it alone!

lol, so you think its got to be something with that is not balanced or somthing that is what i think.

lol, so you think its got to be something with that is not balanced or somthing that is what i think.

makes sense to me...

what i did not mention but i should have was, when the clutch is pushed in and the engine is revved it does not shake it revs fine or when the trans is in nutral, so from my under standing it cant be the engine or the clutch or fly wheel it should shake when i rev it right, but also when the trans is in nutral the trans still spinns right it just not turning the wheels or drive shaft, so whith that would you guys say it has to ether be the trans or back. im going to put the rear end on jacks tomorow and put it in gear and see if it still shakes, thanks.

could be the drive shaft too.

ok i just jacked it up and put it in first gear and ran it, and i also reved the engine nothing happend it did not shake really bad at all, what the fuck any ideas now. thanks

Driveshaft out of balance, or bad u-joints.

i dont know how acurate this is, but ive heard that sometimes just detaching the driveshaft and turning it over will make it turn smoother...

it did not shake really bad at all

But it did shake correct? A small visible shake will be horible under load and driving. When a driveshaft is out of balance you cannot really see it shake, but you can damn sure feel it. It cant cost much to have your driveshaft checked, and new u-joints while its out wont cost alot either.

i think its the u joint, i did not touch the drive shaft since last year it just ben sitting there, and i did mess with the front u joint. i lost the u joint ends for the slip yoke, so i just bought a new u joint and used those end joint instead of takeing the hole u joint out, do you think that could be it. thanks

Did you replace all 4 end caps? Did you use new or old needle bearings? Are you sure you have all the bearings in the cap? I bought a U-joint from NAPA a while back that was missing a needle bearing in one of the caps. Generally if a u-joint is gonna cause vibration then it will be very stiff moving or lacking bearings. But it could be the u-joint. Check the rear u-joint as well though.

no i did not just 2 of them, and they were new, and im pritty sure they were all there. also should i get both of them replaced, would it matter if one is stock and the other one is new or something thanks.

Well you dont have a 1000hp dragster so no it wont matter as long as they are both good.