[Dennis Parker]

89 Bronco, engine EFI, 302 Roller from 87 Tbird, original bronco intake, zf5 manual transmission, putting gt40p heads on her.

Since pulled old heads checked lifters and looked through the holes to check cam some have heavy pitting and all excessive wear. Need to replace cam and lifters. Looking for recommendations on lift and duration... Or stock lift and duration for 87 tbird 302 roller engine...

Thank you in advance back to my own research on the matter.

 

[Dennis Parker]

Sorry rocker arm ratio will be 1.6:1

 

[BigBlue 94]

Comp 35-512-8 is a 351/302 h.o. roller cam that is speed density friendly. It's about as aggressive as the SD system for a 351 bronco will handle.

I'm not sure what firing order you have, but it's fairly easy to swap.

Lobe separation and duration are the limiting factors for the speed density system. For a 351 in 94 that is and lsa of 114° or higher, and I believe a duration about 224 (dont quote me on that)

 

[Dennis Parker]

What kind of RPM range does that have? I drive a lot of highway miles as a traveling millwright. I'm building this to handle the road as well as medium off road. just put in the zf5 havent had a chance to see if it dropped my 75mph rpm of 3k down yet before i started this. First attempt at a cam replacement in a vehicle...

 

[BigBlue 94]

Iirc, its 1500-5500.

Comp themselves suggested it for my application: 351, higher compression with AFR aluminum heads, eddy intake, longtube headers, e4od, 4.88s, and 37s. Mud, towing, and highway driving. I drive 45 minutes of highway daily.

The zf overdrive should drop that 3000rpm to about 2400.

 

[fodder]

I called Comp Cams during my SD-MAF transition (sounds like I just came out of the closet!) and asked if the 35-512-8 would be best for my application. I started listing specifics of the build and didn't get the impression the guy was listening all that close before saying it was the perfect choice, and better than a custom grind unless chasing every last bit of performance. I wasn't 100% reassured by that, but at least it is their top recommendation.

 

[Dennis Parker]

Thanks everyone got a lot to think about...

 

[BigBlue 94]

I called Comp Cams during my SD-MAF transition (sounds like I just came out of the closet!) and asked if the 35-512-8 would be best for my application. I started listing specifics of the build and didn't get the impression the guy was listening all that close before saying it was the perfect choice, and better than a custom grind unless chasing every last bit of performance. I wasn't 100% reassured by that, but at least it is their top recommendation.

My recommendation from comp was about 10 years ago for that cam, and was done over the internet, not phone. It will run on a factory SD system too.

 

[fodder]

My recommendation from comp was about 10 years ago for that cam...

My first thought was, "Damn, they've been recommending the same thing for that long? No wonder the guy didn't give it much thought." But after another 13 seconds of reflection, I came to the conclusion that that's a good thing. If it's good enough to be their top recommendation, what is there to improve upon 10 years later?

BTW, I have one on the way. Bit of an impulse buy the other day, being too good of a price to pass up on a new in box 35-512-8 from a private party. Do you happen to recall if there are any markings to look for, to ensure it's authentic and the right grind?

 

[BigBlue 94]

My first thought was, "Damn, they've been recommending the same thing for that long? No wonder the guy didn't give it much thought." But after another 13 seconds of reflection, I came to the conclusion that that's a good thing. If it's good enough to be their top recommendation, what is there to improve upon 10 years later?

BTW, I have one on the way. Bit of an impulse buy the other day, being too good of a price to pass up on a new in box 35-512-8 from a private party. Do you happen to recall if there are any markings to look for, to ensure it's authentic and the right grind?

Lol I actually had a spare cam burn in that fire too. As far as markings, I can't be of any help. I was too young then to take the time to look for such things. Make sure it is in or with the box, and has the cam card with it. Otherwise, I'd pass.

 

[fodder]

^ Damn, that fire added insult to injury, taking out spare parts, as well.

The one I bought has the correct box with the 35-512-8 info on the end, and I can see some paperwork in the box, but I didn't think to ask about a cam card specifically. If the cam itself isn't marked, I figure I'll be calling up Comp to ask how to verify that the right thing is in the box. I should have it sometime this week. I set aside the head porting project for awhile to fiddle with MAF conversions and York OBA installations, so I still need to finish that up before there's any urgency to playing with the cam.

 

[BigBlue 94]

^ Damn, that fire added insult to injury, taking out spare parts, as well.

The one I bought has the correct box with the 35-512-8 info on the end, and I can see some paperwork in the box, but I didn't think to ask about a cam card specifically. If the cam itself isn't marked, I figure I'll be calling up Comp to ask how to verify that the right thing is in the box. I should have it sometime this week. I set aside the head porting project for awhile to fiddle with MAF conversions and York OBA installations, so I still need to finish that up before there's any urgency to playing with the cam.

If it still has a labeled box, your chances are good. If it's still shrink wrapped and in grease, your chances are higher.

Hah! You dont even know... a full set of xlt interior topper trim in the ultra rare blue color, Ramsey and HF winches, stuffed rainbow trout from when I was ten, first deer antlers, my Ford pedal tractor, all my grandpas reloading supplies and notes, chunks of obsidian worked and brought to Kansas from who knows where which I dug out of the ground, grandpa's tools... I could go on and on. 3000sq ft can hold a lot of memorable material items. What's important in the end, is no one was injured.

 

[fodder]

Yeah, it's in the blue plastic bag (opened for pics) and looks freshly greased -- no sign of ever having been run -- and the visible portion looks the same as the pic on Comp's website. My guess is it'll be fine. Just wanna make sure of it before going to all the install trouble.

We survived two house fires, so I sort of feel your pain. I was too young to remember, so that's a bit different... First our house burned down, then my aunt & uncle's while we were away, with the remainder of our stuff from the first fire. Good thing we didn't have much to lose. :/

 

[fodder]

My 35-512-8 arrived yesterday and the markings check out. No cam card in the box, but at least I got stickers.

 

[BigBlue 94]

Steekers!

That cam will definitely run better on MAF than SD. For MAF, it's not a very aggressive cam, but for SD, it's about as wild as you can go with correct specs.

 

[Dennis Parker]

got my Cam installed, new lifters and push rods and rocker arms. Gt40p heads reworked with the springs in the comp cam kit, new timing gears and chain installed with the full comp cams kit... replaced complete ac system as well, and new water pump and timing cover, finishing touches installing new thermostat housing with sensor for the electric fan and new radiator/heater hoses... going to replace the vacuum lines with rubber ones, one question though:

the gt40p heads do not come with inlets for the thermactor cross over tube so i figured i would leave it out however i wish to keep the rest of the smog system. without this tube what am I to do with the Thermactor Air Diverter valve and the hoses leading to it and especially the vacuum line leading to the valve?

 

[fodder]

You could probably put blanking plates on the ends of the two pipes that would normally feed into the back of the heads, assuming there's enough wiggle room to push them back that far. I'm thinking the system would still happily control the solenoid, not knowing the air isn't going anywhere, but I could be wrong.

 

[TS 90F150]

Sounding good. Excited waiting for updates on how everything runs.

tim