Planning For Improvements
First of all, we knew we needed to replace the exhaust valves. A quick check on the parts shelf netted the required pieces-no need to buy valves. The camshaft was the original piece with enough miles on it to make anyone wonder how many would be left. So we needed a cam. If we're changing the cam, we would need springs as well. With very little coaxing, we decided on a big stick. What about headwork? If we shave some metal off of the heads, we could bump up the compression a little. If we did a little port work, we could make them flow better. Decision made: Headwork was a must. What about the intake and carb? The intake we had been using was an Edelbrock Performer. While this is a good dual-plane intake for engines making power in the idle-to-5,500-rpm range, we wanted to twist this one a little farther than that. The carb we had was a Holley 4150 model with a 650-cfm flow rating from Holley's HP series. Decision: We needed to change the intake, but the carb could stay. We were planning to twist our 360 up to the 6,000-rpm range. With the stock rods and pistons, we thought that would be close enough to the edge without crossing the line into destruction. With that in mind, we decided on a camshaft from Lunati. Camshaft No. 07402 is a hydraulic flat-tappet piece with a 2,500-6,200 rpm range, a .285/.285 advertised duration, and .235/.235-degrees duration at .050. Lift comes in at a hefty .507/.507-inch, with a 104-degree centerline, and a 108-degree lobe separation. Let's not get into a debate whether it's streetable; that's what we chose. The Lunati we chose is comparable to the MP 509 stick, but has a little less duration at .050, with its .235 as opposed to the MP's .248.

Porting 101
The "J" heads that our 360 has are the same basic heads as the highly sought after "X" heads, with the exception of a 1.88 intake valve instead of a 2.02. Even with its fairly good airflow capabilities for an engine of this nature, a little port work consisting of gasket matching and removing some of the "pinch" at the pushrod location was about all we were going to do. To save a little money, I did the basic porting myself. Then the heads were given to Jerry Wilt at Wilt Engine Services in Lakeland, Florida. We had Jerry shave .020 inch from the deck surface. Any more than that and the possibility of intake alignment becomes an issue. We also needed the new valvesprings installed and the guides machined for new positive locking seals. The reason the guides needed machining was the stock valvesprings are a single spring and the Lunati springs for the new cam are a triple spring. Room needed to be made for the smaller inner diameter of the spring and the positive locking seals as apposed to the stock umbrella-type seals. Also, since we are using "seasoned" valves, a three-angle valve job wouldn't hurt either. We also got new retainers for the springs and then had Jerry assemble the whole mess.

Piecing The Puzzle Together
With all the pieces back at the shop, it was time to put it all back together. We first installed the Lunati cam and degreed it in according to the cam card. Next, we used Fel-Pro head gaskets (PN 1008) with a crush thickness of .039 between the block and the heads. The pistons are around .080 in the hole, and in hindsight, the MP Gaskets (PN P4120094) may have been a better choice. The MP gaskets have a crush thickness of .024-.028. That would have bumped the compression just slightly higher and helped the quench a little. With the heads bolted back on using the stock head bolts, the intake-a Weiand X-CELerator single-plane PN 7545-was gasket matched and installed. The X-CELerator is a good intake for the 1,500-7,000 rpm range, and the square-bore mounting flange meant we wouldn't need an adapter plate to mount the carb.