So I picked up a 302 roller motor the other day with only 60,000 miles on it for 250$! I'm gettin it ready to go in my 89 f150 on 42s so I figured while I got the time and got it out why not freshin it up a bit and give it a little more ummff! Well so far I picked up a set of gt40p heads and and I wanna add a mild cam, I don't want anything major it'll still be on the speed density system and I do drive it on and off the road quite a bit. Iv been lookin at the comp XE264HR cam and it seems to be pretty much what I'm lookin for. Question is will this cam alone work with stock gt40p heads or am I gonna need to change springs/lifters/rocker arms.. Ect ect..? I'd like to keep them stock if possible and also I'll be running long tube headers what kinda gains will this set up give me?? Thanks!
That will run on SD but I think it will be pushing the limits of the system It would be a good idea if you installed a wideband O2 sensor to keep an eye on the Air/fuel ratio, if it goes lean at higher rpms you can try an adjustable FPR to raise fuel pressure a little from stock.
As for the heads, I don 't believe the stock springs will support the lift that cam generates so an aftermarket spring setup will be needed. No need for anything but stock rockers and pushrods however.
Well on comps website it says that cam should be used with 1.7 rockers and I believe that the stock ones on gt40p heads are 1.6.. ? So if I use it with the stock rockers it'll bring the lift of the cam from .544 to like .512...right? So would I still need new springs? and second I read everywhere people say stay with a lsa of 114* with speed density but this cam has a lsa of 112*.. Would that cause a problem?
Well iv got the cam in and now my pushrods seem too short.. And also since I'm using the stock 1.6 rocker arms with the cam will I still need to upgrade valve springs? I really want to stay with the stock ones if possible..
I knew if I went with the 1.7s if have to upgrade but I was hoping that with 1.6s I could get away with it. If I decide to go 1.7s anyway why are some good springs? Comp recommends some dual springs but I'd rather stay with some single trick flows or somthin that will work with my heads how they are
Well iv got the cam in and now my pushrods seem too short..
You are using roller lifters with that cam right?
Originally Posted by brandon mauldin
And also since I'm using the stock 1.6 rocker arms with the cam will I still need to upgrade valve springs? I really want to stay with the stock ones if possible..
Stock springs may "work" but they are pretty weak and will allow valve float at higher RPMs, stiffer single springs are my suggestion as doubles will most likely require machineing of the spring seats.