Ok, here's the deal.....Im in the process of putting an LS1/T56 setup in my 91 Z28. However, until I get room in the garage and time to do it, I need some heads for my 91 L98. I changed plugs in it yesterday only to find out the valve seals are shot totally now. I saw some 305 heads on the classified and was wondering if they would work? Im not looking to put a bunch of money into the L98, but would like to put something decent on it for now. Could anybody suggest some good heads I could get for around $100-200??? Thanks in advance

 

If you are only doing it for temporary, they should be fine. You might notice a little loss in performance with the smaller valve size. Then again I may be wrong. You would be bumping the compression up a little bit. You should be able to get a set for real cheap if you look around.

 

actually the ones I found were ported and had 1.94/1.50 valves in them, minus rocker arms, which i thought maybe I would splurge and get some 1.6's??? Would that be ok? would I lose or gain power???? I know bumping up compression would help some.....

 

That's great if they have already had large valves installed. The 1:6 rockers won't hurt. Especially if you have a stock cam.

 

Why not just replace the valve seals in the L98 Heads ?

 

Well, I was just curious. I was gonna just replace the seals, but I figured all the work to get the heads off and the labor, why not see if I could find a little better set of heads if I could. I had also heard that the 305 heads flow better, and raising the compression wouldnt hurt either...... Is it possible to gain say 10-20hp doing this?

 

If you really mean the seals and not the guides, then all it takes is an air compressor, a valve spring removeable tool, and about 3 hours.

 

Well, the guides wont cause it to foul out the plugs would they? I was thinking more the seals because it smokes a little when its first started after sitting a while, and the plugs had oil on them(not alot, just enough to foul them out).......If its the guides, how hard is that to change, or wouldnt I be better off to just replace the whole head?

 

Like I said, its easy, just a little time consuming to get to them.

they cost about 20$ from the local parts house, too.

 

Better check with some professionals. The 305 heads are 55-58cc depending on year and custom work. In fact I'd expect the compression would be too high for iron heads if you have stock pistons.

my .02 cents worth,
RP.

 

if the seals are leaking bad enough then the oil drippin will cause it to foul of plugs... mine do it... but i am in the process of doing a 383... so i am not worrying to bad about the leak... or if it fouls off a plug.... its only happened once in like 5 months!!