I'm thinking of adding on 1.7 roller rockers. Is it a good mod for a pretty much stock motor. Does it make a difference? What does the labor cost go for? My current mods are frpp cobra intake bbk cai fms 65 mm tb 3.73 gears a hyper tech chip and catback exhaust.
How many miles are there on your motor? YOur valve springs may not like the 1.7 ratio with there age. I would personally wait on them till I did the heads (get stud mount heads and stud mount rockers, your current heads are pedestal mount). Theres also not a lot of hp gain in them. They can help reduce valve tip wear on motors with big lift cams and heavy valve springs, but that doesnt apply to you.
Oh and welcome to Stangnet. Better late than never.
The valve lift with the stock cam is increased from 0.444" to 0.472" by the 1.7 ratio rockers, and they also increase 0.050" lift cam duration by 3 degrees. The effect is like having a slightly bigger cam, and the result is something like a 6rwhp gain at higher revs but a slight torque loss lower down. It's a waste of time/money if you have stock, unported heads that are flow-limited at higher valve lifts. If you port the stock heads, higher ratio rockers would work better.
Ok I'll just stay away from them than. I don't plan on adding a cam, Not sure about heads yet. I don't want to have to deal with all the tunning bussiness.
If you do go for the Cobra 1.7 roller rockers while you have the stock heads and later decide to upgrade to aftermarket aluminium heads, you won't be able to reuse those rockers unless you choose pedestal mount heads (most are stud mount). Your choice of camshaft will also be restricted to one that has less than 0.500" of valve lift with 1.6 ratio rockers so that you don't run into piston-to-valve clearance problems.
If aluminium heads are definitely in your plans, I'd follow Grady's advice and get stud mount heads with 1.6 ratio stud mount roller rockers. The stud mount heads already have pushrod guideplates and rocker studs, while the main advantage of the stud mount rockers is their adjustability, thus making it easy to set the lifter preload without needing to buy pedestal shims or different length pushrods. The TFS and Holley top end kits already include fully assembled heads, stud mount roller rockers, hardened pushrods, and taller valve covers so you don't need to piece everything together.