Lt Mac Mac Have Mark spend some money and have the head get some work. Clean up the ports to match the intake. Clean under the valves to increase and smooth the flow into the cylinders. Most guys here call it a stage 2 job. You are not looking for max flow on these heads. Maybe down the road. I am guessing you had a finger problem with the spec numbers and the block is a 4.05. Walls should be plenty thick.
I would recommend that you have the block bored and buy a complete rotating assembly. This assembly should be balanced with the crankshaft dampener and flywheel. This will save alot of time in the long run. The main bearings, rod bearings, and rings come in the kit. You will have to check the clearances on them. Rings may need to be trimmed for the clearances. Need to tell the machinist what material the rings you are running to match the cylinder honing and for a quick breakin. This way the motor will not use alot of
oil.
Valve springs, your friend is building a torque motor with a stroker setup. IMO I don't like to spin one over 6,000 rpms at all because of high piston loads. It would cost extra money but running a set of beehive valve spring from crane #12026 for a BBC would be perfect. These are the ones I have been running for better than 10 years. The less weight in the valve train the quicker the motor revs. Pac springs also sells a spring in the 420# range which will get you to 6,300 rpms. The other problem is your heads running out of air along with the intake. Intake runners and ports can cause from 10-40 cfm different in flow between each cylinder. There is a guy Joe Craine that match ports an intake. Job is super and all the ports are within 5 cfms. Takes about a week and worth every penny. Power increase 5-20% depending on heads work done.
Camshafts IMO rollers are the only way to go in todays world. The
oil has changed so much with removal of protective
zinc particals. There are a couple of guys sell
oil with high
zinc and the other elements to protect like Joe Gibbs. This stuff is not cheap.
Amsoil is another. You didn't say what oil you guys where looking at. Either way buy breakin oil and do the 20 minutes at 2,000 rpms. Change the oil and open the filter and check for metal flakes or partials in the paper. Some guys run Mobil 1. I have never tryed this on my race motors or even in my cars and trucks. I have tested my own fleet and found that Lucas oil suppliment works greats. Use 1 quart with each oil change. Motor oil must be warm and pour in slowly to get a good mix. startups will not be so dry and rockers will be quiet.
Back to camshafts rollers, hydros. These are the heaviest 0f the lifters. Solid roller are lighter and they have there draw backs. Can be run on the street but have rules about no idling and checking valve lash. Life time limit is about 10K miles and then start to check rollers and camshaft ramps. The lash causes hammering of the wheel against the lobe of the shaft. It's only .016" cold lash but there is still hitting of the rocker, pushrod and lifter. It's wears out. For what you are looking for, a roller cam with a max of .600" with a 112 LSA. The small crane 587-607 would be ideal for you. Little lope and alot of mid range power. Custom camshaft will get a little more power from the same range. Buy a good set of timing chain and gears . Get a torrington bearing kit to hold the camshaft in place. make sure you check the end play of the camshaft, it may need to be shimmed to remove free play. Gear on the distributor, Make sure you match materials or you will have problems down the road. Cutting info short. Lt thanks for servicing us and good luck. Rick L.
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