I just had a set of heads milled .015 and had a performance grind done on the valves. The shop had a guy bring in a brand new set of Mopar 1.7 rr's with the pushrods and they'll sell it to me for $150 bucks. My question is with the 1.7's will fuel mileage decrease? Is there a noticeable difference in performance? And I am assuming i have to get the mopar performance valve covers for them to fit. And would i need to put clay on the piston to make sure i dont have the valves hitting since the heads were milled .015? (Current setup is the the head work/hughes air gap/edelbrock headers/50mm throttle body--soon after ill be looking at 4.56 gears and 35's, if i get an SCT itll be a few months or so)

 

from what ive heard you need the sct to get the truck to run right with the 1.7's, did they happen to gasket match/port and polish the heads to motor/air gap?

all in all it sounds like it will be a completely different truck when your done!

 

You won't have to worry about PV clearance with 1.7s, even if the heads were milled .15.

You don't need the SCT to tune it with 1.7s, but it would help in that an SCT helps a stock truck, where you do need the SCT is with the intake manifold already installed.

I have a pair of Mopar Magnum valve covers for sale in the 4 sale thread.

 

I was going to have them port and polished to match the intake, but to be honest there was barely any difference between the air gap ports and the intake ports on the head. With out running a larger cam that tiny bit of difference that was there wouldn't of benefited to much.


im just trying to decide if its even worth my time putting those 1.7's in there. The trucks my daily driver and tows occasionally. I thought i read somewhere on here that they drop fuel mileage but im not sure if thats true or not. Do the 1.7s make a big difference or is it hardly noticeable?

 

They make a difference, but, how noticeable it is, depends a lot on what else you do at the same time.... every little bit helps. With the better intake, they will help even more. (basically makes the motor think you have a slightly larger cam, with more lift, and slightly longer duration at .050.)

Is it worth it? Well, folks have spent more, and gotten less return on their investment power-wise..... so, that one is really up to you.

 

For 150.00...I'd do it in heart beat as long as they came with guide plates etc...

 

Missed the cheap price. In that case, I will second this motion.

 

thats a great deal and a great bang for the buck

 

do i need to change the springs?

 

Shouldn't have to.