Need cam recommendations for intake project

[Griff5.0]

First post on this sight:

I've got an S-Trim vortech (stock pulley) sitting on a mostly stock '93 LX AOD (3.73 gears, headers, cat-back) I'm upgrading the entire intake with the application documented below and need to determine the correct cam to top it all off. This is a daily driver and I don't intend to bring it to the track. I assume this suggests a more torquey and low-range power band for my project's application.

Pending upgrade:
Stage three ported GT40P heads
Pro_M 80 Mass Air
UPR 4" boostmaster
70 mm throttle body
Cobra Intake
42# injectors
Upgraded aod

I'm looking for some recommendations for a new cam given the above application. Has anybody built an application similar to this? I'd like to learn from your experiences.

Thanks,

[fanglemeister]

The cam you run will also depend on the stall speed of your converter. For near stock stall or slightly higher than stock, up to @ 2500 stall, my #1 cam selection for the street has always been the "baby" Crower cam #15510: that is a 212/212^ @ .050", .533/.533" lift, 114^ LSA grind (or similar from another company). It has proven itself the perfect 5.0L street cam time after time, whether n/a or boosted.

Assuming you will be going with a slightly higher, 2500-3500 stall, and since you have the 3.73s, might want to consider the Comp Cams #XE270HR-14: 218/224^ @ .050", .512/.512" lift, 114 LSA.

But really, anything with intake duration in the 212-218 range, total lift circa .5" inch, and 112 or 114 LSA will suit your street application just fine.

With the GT40P heads, even ported, you won't gain any more flow by going with lift over .5" to .525". The duration will determine your shift points, you want this to be well matched to the Cobra intake, which is all but done at 5500 rpm, so the duration should be in the 212-218 range -- anything higher will lose low end torque in exchange for 6000+ rev capability. The 212 cam will pull well from 2000 to 5500 and the 218 cam will pull hard from 2500 to 5800. When you get into the 222 to 232 @ .050 duration range you are looking at 6200 to 6500 redline, and being down 20-40 FtLb at 1800-2500 rpm. The 114 LSA (lobe separation angle) helps smooth out the idle and broaden the torque curve, 112 LSA is also acceptable for mild boost 5.0Ls, but anything with 110 or less LSA is going to start bleeding off boost out the exhaust during the overlap period.

[Griff5.0]

Thanks for the reply Chris, but I've got an unanticipated change in my application. I bought the heads sight unseen off of Ebay and had them shipped directly to my engine builder (I never saw them). He just informed me that they are not P-heads, but instead, are the standard GT-40 iron heads (stage 3 ported).

Do you have any cam recommendations for stage 3 ported GT40 iron heads? FYI, your assumption of a higher stall converter was accurate. I don't recall the stall speed, but I think your estimated range is pretty accurate.

[fanglemeister]

The cam selected should be about the same for ported Ps or GT40s. I'm running lightly ported Lightning heads (GT40s with 1/2" bolt holes, 188/152 flow), they level out at .5", they flow basically the same amount at .55" and drop off slightly at .6".

I have an Ultradyne 282HR12 in mine, 216/216 x .512/.512" 112LSA, I like it but they seem to be out of business at this time.