is it still cool to put a different cam in my 85 firebird's 305 engine with 250,000 miles??? just want to know....get at me fast

 

If the cam bearings are in good condition it should be no problem. Of course you will have to install new lifters and break in the cam properly, then drive it as usual.

 

do you really think.. the rings and bearings will last long after a fresh cam

 

The bottom end and all other parts will last just as long with a new cam as they would have with the original cam. The cam doesn't impart any load on the rotating assembly other than to rob power from it for spinning the cam. That won't affect rings and bearings at all.

However, if you are asking whether the owner will now tend to drive the car harder with a different cam and whether a resultant higher load may affect rings and bearings, that is a greater probability. Rings are usually forced outward by gas pressure and cooled/lubricated by engine oil. While good lubrication will be important higher gas pressure from harder driving may wear the rings faster.

Also, higher load on the crank may increase the risk of shearing the oil film on main and rod bearings and causing wear. Again, good lubrication will be important.

I had a 110+K LT1 beaten on reguilarly (after it was fully warmed, every time) and everything from rings to bearings to bores measured within the factory BUILD tolerances) not the wear limits, but blueprint build specs) when it was torn down at 110+K. Of course, that was 110+K on Mobil 1 instead of oil. I would expect an engine like that to last 300K with whatever cam you could fit into it.

 

Cam bearings in my 160K mile L98 looked pretty suspect so I never did the cam swap. Just did a 383 instead If the bearings look good then go for it. Probably not going to look good tho.

 

I went with a different decesion....I left the stock cam in there didnt even f u c k wit it.....I installed new HP pump up lifters, 7.900" pushrods with valve guides, roller tip rockers, and a noisy gear drive....and during the processe i installed a troker II manifold and a 750cfm edelbrock carb....believe it or not my lil 305 hauls *** now lol

 

Not trying to come across as a jerk, but a 750 cfm carb doesn't sound ideal on a 305. And a torker II doesn't belong on ANYTHING... And cams and lifters should be replaced at the same time

 

I dont personally belive a 750 belongs on anything under 400ci. My 383 probably dosent need the 750dp its got on it now, must less a 305. Torkers ARE junk. And you should have just swapped the cam while you were at it. I dont see much of a problem just replacing the lifters since you do have a roller, but you had mights as well swapped it while it was all apart. And last, the gear drive dosent do much of anythng for performance, i dont see how the 305 is "haulin ***", just because you added an intake thats worse than the stock one, a carb thats EXTREMELY to big for it, gear drive, and a set of lifters. I just cant comprehend.

 

You'd change your tune if you had a minute with a properly built 305.

 

Atilla is right. My old 305 with only bolt on mods, and 147k on it really does move quite well. I would like to think That it is tuned right for the work ive done to it. It doesnt take much in the way of bolt on parts to get them working better than anyone could imagine. I cant say I would use a 750 on one, but then again Ive never tried it. If my poor old 305 didnt need a full rebuild, I would consider doing more with it.