Help with Cam Selection For my 94 Z71 Build

[xx94Z71xx]

hi guys so i have a dilema here. trying to decide which cam to get for my 94 Z71 Build. The Block is a Early 2Pc Rear Main 355. Im using just simple flat top pistons from engintech. The heads i want to use are 217 heads which are off a Gm crate motor and are like L98 Corvette Heads just iron. pretty sure the are 64cc.

i want to run just a little better than stock cam. im trying to do as little as possible to the computer and am shooting for 260 to 300hp and want to keep the reliability of the stock system. im either going to run the stock manifold, or will convert a Edelbrock performer 4 barrel manifold i have here. will be using short tube headers to y pipe to a cherry bomb for the exhaust. I already have a 17PSI 255LPH external pump installed, so i will probably try to source some 80lb injectors

heres a few of the cams im looking at

https://www.ebay.com/itm/Lunati-Bar...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

https://www.speedwaymotors.com/COMP...ergy-Hydraulic-Camshaft-Chevy-S-B,217567.html

https://www.ebay.com/itm/Chevy-GMC-...h=item2329ccb629:g:Rv8AAOSwESNZ70iB:rk:1:pf:0.


Any input is appreciated. i dont mind if i have to get a basic computer tune, but dont want to be messing with it 24/7. heres a few pics of where im at

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

 

[xx94Z71xx]

bump. anyone have any ideas??

 

[89GMCJOHN]

They are all so close it probably wont matter in the end but I would go with that 3rd one …..I like that its on a 110.....will bring the torque in a tad earlier .

 

[xx94Z71xx]

thanks for your input, im either going to go with the tor the lunati i think. i know they arent much different and i was just looking for someones input who may have used one of the ones i listed. Should be ordering one tonight.

 

[wheelman]

Are you sure about flat top pistons.what will the compression be.im just wondering if the valves will hit.i remember getting the compression up.by shaving the heads.not changing pistons.

 

[98 Nitro]

He should be fine, Caprice tbi motors had flat tops, but I don't think he needs big block injectors for a mildly built 350.
The best tbi cam without alot of tuning is suppose to be Lunatis smallest Voodoo cam, it's basically a newer version of the old 204/214 RV cam many use.

 

[L31MaxExpress]

You have left too many variables out to help with the cam selection.

A flat top piston with a 1.54" compression height in a stock deck block ends up about 0.050" down the bore and using a rebuilder .043" compressed head gasket ends up close to 9.1:1. Zero decked with a 1.56" compression height piston and a .038" gasket ends up about 10.3:1. Makes a HUGE difference when factoring in DCR and fuel octane requirement.

Transmission, Gearing, Tire size, and expected use will also factor heavily into the cam choice.

You do not need bigger injectors until you get over 400 HP. Even the 400 HP Marine 502 only used 61# injectors but ran them at 28-32 psi.

 

[xx94Z71xx]

hey guys i ordered the Lunati Cam i had listed above and it should be here by friday. and when i calculated my compression i ended up around just under 10:1. The flat tops i use also have dome volume of 6 they and pretty deep reliefs shouldnt hit the pistons. im not looking for crazy HP i want to get up around 300 or a bit more. good to know that i shouldnt need bigger injectors. i would like to put a fuel pressure gauge in and a AFPR. im more concerned about how the computer is going to handle everything. i want it reliable as i plan to daily drive it again. i dont know a whole lot about these computers.


im leaving the rest of the truck pretty much stock, its 4x4 342 gears 4l60E factory 265/75/r16 tires. ive had the truck 5 years. it was brought to ny from virginia in 2014 and is really clean. motor is toast runs good but keeps eating head gaskets. the deck isnt flat and needs machining. to me its really a boat anchor at this point.


i plan on ordering these headers next


. https://www.ebay.com/itm/FOR-88-97-CHEVY-GMC-C-K-GMT400-5-0-5-7-V8-PICKUP-TRUCK-SUV-STAINLESS-HEADER-BOLT/191138890073?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

 

[David Barry]

From all that I've read, your computer should handle any cam with an intake duration at .050 of 206 or below. I just ordered the Comp Cam 12-249-4 for my '93 350 Sierra. The same one you listed as a second choice. You may have dodged a bullet by staying away from your third choice with a lobe separation of 110 degrees. I believe you should stay at 112 or above. The OBD1 set up on our computers is suppose to be a bit flexible, yet very basic. I could only find one mechanic in the Phoenix area who said he could work with it. He was charging well over a grand. Others I called had thrown out OBD1 testing equipment years ago. I'm refraining from replacing the heads for this reason. I had 342 rear gears changed out to 4.10. It cost me a grand and I'm glad to have made the move. I drive mostly around town, so my gas mileage should not suffer too much. I too, have oversized tires (265-65-18). I made changes in the VSSB calibration to get my speedometer, odometer, etc. realigned to be more accurate.

 

[L31MaxExpress]

From all that I've read, your computer should handle any cam with an intake duration at .050 of 206 or below. I just ordered the Comp Cam 12-249-4 for my '93 350 Sierra. The same one you listed as a second choice. You may have dodged a bullet by staying away from your third choice with a lobe separation of 110 degrees. I believe you should stay at 112 or above. The OBD1 set up on our computers is suppose to be a bit flexible, yet very basic. I could only find one mechanic in the Phoenix area who said he could work with it. He was charging well over a grand. Others I called had thrown out OBD1 testing equipment years ago. I'm refraining from replacing the heads for this reason. I had 342 rear gears changed out to 4.10. It cost me a grand and I'm glad to have made the move. I drive mostly around town, so my gas mileage should not suffer too much. I too, have oversized tires (265-65-18). I made changes in the VSSB calibration to get my speedometer, odometer, etc. realigned to be more accurate.

LSA you can run depends on the duration. The stock GM 305 TBI cams are on a 109* LSA. The stock GM TBI Marine 305 and 350 cams are also on a 109 LSA.

The nice thing about OBD1 stuff is the equipment to tune them is still available and not nearly as expensive as the OBD2 stuff.

I real time tune my OBD1 stuff with a Moates Autoprom Emulator.

You must be registered for see images attach

You must be registered for see images attach