I have an 84 Trans am with a 350, its an 84 as well for all you smart *** people who reply with "84's dont have 350's, are you sure its an 84?''. Anyway, I have an edlebrock rpm air gap manifold, holley 750 double pumper, holley 130 gph fuel pump, full msd setup: distributor, control module, coil, wires, comp cam 280 avg.duration, dual 12 electric fan. As far as the heads go they are just stock. Should I get new ones? I was just thinking of buying some comp 1.6 full roller rockers and calling it good?

 

Its an '84... are you sure its a 350?

Anyway... as for 'stock' heads - depends which stock heads. Some 350s has terrible heads, like the 882 or 624 castings, and some were pretty good like the 083 or Vortec heads.

Whats the casting number on your heads? Get the last 3 digits of the long number inbetween the valve springs. You'll have to remove one of the valve covers to get it.

 

yea, 350's didn't come is 84's.

i agree with adam, what are the casting numbers for the heads, and what are the complete cam specs.

 

Im not sure about the heads, Ill pull a valve cover off and check. As far as the cam, adv. duration: 280, dur@ .050: 231, lobe separation: 110, valve lift: .480, lob lift: 0.32, Its a magnum hydraulic flat tappet cam.

 

If duration at .050" is 231*, then thats a pretty healthy cam. Similar to what I have in my 350. You'll want a minimum of 9.5:1 with a 350 for that cam, but it would be happiest around 10.25:1 or so. A cam that size makes for a really nice street/strip 350, but biased abit towards 'strip'.

Ignore 'advertised duration' as its basically meaningless. 'duration @ .050' is the important one, as its the industry standard measurement, so its the only way to get a real idea of how big a cam is.

I have an XE274 (very similar in size to yours) in my 350, and I used a set of '601' casting 305 heads and it worked VERY well, though it had to be very conservatively tuned to run on pump gas, as the compression ratio was a little over 11:1. I have a set of World 200cc heads now and the compression is right around 10:1. Now the cam really works nicely that the compression ratio is in the right place.

 

So exactly what kind of heads would I need to get and where would I get them to achieve about 11:1 compression? I would want them to be assembled except for the rocker arms, because I want to put some comp ones on. Im looking on ebay and need to know what casting number I should be looking for besides 601 and what ones should I avoid?

 

What style of pistons do you have? That will play a big part. If you don't want to go aftermarket, look for a factory head with 58-64cc chambers. Those should get you into the 9.5-10:1 range generally, if the piston dish isn't too big. 416, 601, 081, 083 are good factory iron castings to use. The 113 aluminum Corvette heads are not a bad choice either. Probably all of the iron heads would have to be modified to handle more valve lift, and screw-in studs would be a good idea too. The aluminum Corvette heads already have this done.

Then theres the aftermarket, but there are just too many to list, as there aren't really any 'bad' ones... just some that are better than others.