newton5.0

hey i am rebuilding a 91 LX and i am putting some GT40 cast heads on it that i am buying from a buddy. Any idea what i will be needing for push rods and rockers?The car already had a big cam in it when i bought it but i am not sure on the size.

jthorn9

Well the rocker lift will be 100% up to you. A dyno posted showed that 1.7s do add power over 1.6s, however it wass marginally so, a few people have also complained of having too rough of an idel with 1.7s, others have had no issues, so again, this one is up to you. Stock rods should do, but if you feel the need, hardened will do just fine as well.

tooslow5.0

stock lenght is good, but keep in mind-what ever amount you have the heads milled, have the shop take the same amount off the top of the valve stems to keep geometry the same. or you will need shorter pushrods.

Joel5.0

You need to check the valve train geometry with an adjustable pushrod to check what's the correct PR length(s) you need to order..... camshaft, heads, rockers, valves...... all affect the PR length requirement.

Mustangkiler

Find out the cam specs before you buy rockers, as for pushrods im guessing the heads are pedestal and probably dont have a stud conversion on it, so you can do what i did, get the ford racing stock length hardenedpushrods and shim it, its worked for me and a few others with gt40 iron and aluminums with steeda and e cam.