I have a 85 Z28 body with a 88 TPI 305 with about 90K on engine transplanted and T56 from a 93 Firebird Formula, 308 posi rear, stock exhaust The engine came from a wreck, the original car had a five speed. I am told that a sudden stop of the drivetrain like from an accident can blow a head gasket. Started using anti-freeze right away and got worse over time. I'm O.K. with this part. My question is how far to go while replacing the head gaskets. Looking for a second opinion I will be meeting with my fathers friend builds engines on a regular basis after the new year to discuss this question. While taking off the heads of course get them checked for cracks, re-seat or replace valves, guides and so on. Timing chain and gears while it's apart seems obvious. Heres the question part: My father suggested while it's apart to consider shaving the heads (more than just true-ing them up) a little to add some compression and get more power as well as using a thin head gasket. Also he suggested while they are off, might as well have them ported for a little better air flow. Seems to make sense.Then we got thinking about how close we would be to the cam. Now I plan on keeping this engine in the car for about five years until I finish school. Would it be worth putting a cam in a set up like this? I heard that the 88 305 engines had soft cam issues as well. If anything I was thinking about a very mild one because I really don't want to go through the bottom end and how much can you even flow a stock exhaust anyway. Bottom end is tight and I just need this engine to last for about five years. I also don't want to have to mess with the computer as I don't know much about them. I know if I put a mild cam in I need to replace the lifters, what about the pushrods, rockers, cam bearings and springs? I do not want to pull the engine again, looks like there would just be enough room to slip it out. I'm not sure if there is a cam that fits my needs. Would like more power but not looking for a race car and I like my fuel economy. I just got the car together this past spring and still have other bugs to work out I but I figure while I have it apart I might as well do it right there's some things you just can't chinse out on. Any thoughts would be helpful.

 

If its indeed an 88 305 it probably has a roller cam with roller lifters. In that case you should be able to use the rockers, pushrods, and lifters if they are all in good shape. it would be a great time for a cam upgrade but that will require tuning the computer to get the most from it. Considering all of the $$$ involved in rebuilding the top end most people would opt for a 350. Milling the heads is a good idea to both clean them up and also to bump compression a bit. Just don't mill them too much. It would be good to change the springs too, but the cam you pick should determine which ones you will need. A timing set would be good while your in there as well. I'd pull the heads and see what your working with first. Once you know you can make the best part decisions.

 

Is there any merit to this engine having a soft cam and the possibility that it's days are numbered?

 

Before spending the money to replace head gaskets on this motor, be sure to pressure test it to verify that the block isnt cracked. Also, check deck height of all pistons to verify no bent rods.

 

I'm not sure what you mean by pressure test the block. Checking deck height I think means to check the height of all of the pistons in relation to the top of the block to make sure they are the same at top dead center, Right? A bent connecting rod would give an off reading.

 

By pressure test, I mean to test for coolant leaks elsewhere that the heads or head gaskets. Of course you'll have the heads pressure tested while theyre off. To test the block for cracks we use magnaflux. The motor is preferrably torn completely down and hot tanked before this. Yes, a bent rod will generally read low compression.

 

I'm doing something similar to my car. I need some head, intake, and header gasket model numbers since I'm having my heads matched while at the shop. Any suggestions?