Cam selection and install

I would definitely put in new springs with the new cam. Preferably the same brand as the cam (install the ones the cam mfg. recommends). You'll also need new lifters for sure, I'd even consider replacing pushrods. At least ask the cam mfg. what they recommend.

If all your stuff is one brand if something brakes you have a better chance of them working with you. If not they'll blame it one one of the other (not theirs) brand components.

Everything in my valvetrain is Comp Cams except the valves and the rocker arms. When Comp Cams ground the cam wrong I had no problem getting them to replace the cam, lifters, and pushrods for free.

As was said previously after the cam install pay carefull attention to breakin. Start the engine and take it to 2000-2500rpm as soon as possible and let it sit there, varying rpm in that range for 30 minutes. Then shut it down change the oil and let it cool completely before running again.

Well, the heads are new to me- does that count? I picked them up for cheap on ebay, and theyre at the shop now getting cleaned up and a basic valve job.

AWhite70's cam actually has a bit more lift with the same duration, I believe. Whats your vote, 79- upgrade springs for another $100 or choose a cam with less lift?

79Nautique, Gottaski and Munday already gave me some helpful tips as I prepare to install a cam on my '90 Nautique, but I figured I would start my own topic.

In the coming months I will be adding GT40P heads and a Weiand Stealth intake manifold. While Ive got that much of the motor apart, Ive decided to add a cam to make the most of the upgrades.

Ive searched this site and found specs for the upgraded cams that several of you are using (79Nautique, AWhite70, captan1) which was a great starting point. I called Comp Cams and got their recommendation, which seems right in line with what others have. Here are the specs:

Grind Number: XM262H
RPM Range: 1300-5500
Duration @.050" (I/E): 218/224
Lift w/ 1.6 Rocker (I/E): .493/.509
LSA: 112 degrees

The cam will still idle nicely, and Im not worried about torque below 1300 RPM since I get an instant 3k RPM coming out of the hole at WOT. My mostly stock motor turns 4600 RPM now with the new prop, so 5k+ with the upgrades is very possible. Overall I think its a good fit.

However, Ive read that the stock valve springs on the GT40P's are only good up to .500 of lift, which I would be exceeding on the exhaust valves. The comp cams tech said that I need upgraded spings regardless of my cam selection. Is this true? Or would I be fine running a cam with slightly less lift?

I would like to do a full rebuild on the motor (1165 hrs) eventually, but not for another 5 years. Would it be worthwhile to put on a new timing chain now, or not bother? I'm leaning towards putting the cam in with new lifters and calling it a day.

When it comes to rejet my carb, I found a full kit from Summit for $40. Should work fine, right?