I have an 86 305 TPI motor and I was wondering what are the different types of heads could I use? Are the 350 heads the same or would I gain just as much by just redoing the 305's. I am on a budget so I was just wondering. I need to redo the seals and possibly the guides so I didn't know what the price would be to just rework these heads if it needed guides or to try and replace them with better ones.
Thanks

 

Those would be 416 castings. Pretty good heads. 58cc chambers, 165cc-ish intake ports, 1.84" intake and 1.50" exhaust valves. Pretty much the same as 350 heads except they have 64cc chambers and 1.94" intake valves.

For what it would cost you to have 1.94" intake valves installed, and to do some basic porting/clean-up work on your heads, you would have much better results on a 305 than you would spending the money on 350 heads and the compression loss you'd take with them. "Better" heads would be more than a 305 TPI would take advantage of, so the cost really wouldn't be worth it.

Those heads with larger valves, upgrade springs, and the porting work I described would support of 350 quite well. So, unless they're cracked or otherwise damaged so that repairing them would be expensive, they are good heads to spend some money on.

 

No the heads are fine the motor just puffs and you can smell a little oil burning through the exhaust. I need to have that fixed so I figured if the guides needed to be replaced I might as well have some work done on them. I just didn't know if it would be advantageous.

Thanks

 

Valve stem seals. Very common. Replacing with positive-sealing type is usually a good idea. The best of those require cutting down the top of the guides so they fit snuggly and cleanly. Might as well put new/better valve springs and retainers on while you're at it. The 1.94" intake valves will help your engine run a little better, and the port/valve pocket clean-up does wonders.

Since the valve stem seals start leaking pretty soon in the engine's life, the guides get a little more lubrication than they were designed to need. So, guides typically don't need to be replaced. But, if they do, this is the perfect time to do all the rest of this.

If all you really want is to stop the oil burning, that can be done without even taking the heads off. The springs have to come off, though, so. . .

 

So...
If I don't have to take the heads off should I just replace the seals, springs, retainers and maybe put in some different ratio rockers? I would just like to stop the oil burning it is quite annoying. I was hoping to do a ls1 swap eventually so I was trying to not do to many upgrades so I could save more money for the swap.

Thanks