4playta

Well I just bought myself a 1988 GTA trans am. As you might know I sold my 1984 last week because I wanted something different.

This is the plan, I am going to pull the motor next week and take it to my local machine shop and have it punched .30 over, install new bearings, forged crank and pistons. When I get my short block back I am going to install vortec heads and a HSR. My compression ratio will be 9.5 to 1. What cam would go best with this combo? And one more question...I am using forged internals because next winter I plan on installing a procharger and will be running about 8 to 10 psi of boost, the question is will the cam thats best for my setup now still be the best choice after procharger is installed?

F-BIRD'88

if you choose a cam that works particularly well over all N/A with the HSR induction, adding a super charger will not change that.
Something with a dual pattern on 112 LSA is good.

five7kid

iTrader: (14)

Better have them only take it .030" over. Go .30" over, and you'll be into water.

4playta

Yeah I ment .030 over for 355cid.

Orr89RocZ

iTrader: (20)

go with a 224/236 blower cam from comp. it will make good power n/a with those vortec heads, as the duration split will help that weaker exhaust port.

its plenty of cam for that compression ratio. Once you go blower, that blower cam will work perfect!

4playta

Will this work with stock vortec heads? I cannot afford anything better at the moment so I plan on running stock vortecs ported and polished but thats about it as far as head work goes. I am sinking most of my budget in the bottom end and the HSR. I figure I can always upgrade to better heads in the future. Anyone have an idea on what kind of power I could expect out of this combo? I hope to get about 350 at the crank NA and maybe 450 to 475 under boost...maybe 500, lol! What my goals are is to build a bullet proof motor that has very good drivability, idle quality, 18 to 20mpg with a 3.23 rear and 700r4 trans.

Orr89RocZ

iTrader: (20)

the cam i listed is a very popular nitrous cam in the LT1 world but also serves as a good blower cam. most supercharged cams are also nitrous cams.

its gonna be a 224/236 on a 113 lsa so its idle friendly thats for sure. lift will be .502/.520 with 1.5 rockers, so the problem is vortec heads as cast cant handle more than .480 lift without retainer to guide clearance issues.

you can get the heads worked over at a machine shop, getting the guides cut down so you can get more lift out of them. If they dont have screw in studs, get them installed for safety as with the blower they will need it.

The cam i list will make good power all the way to 6000rpms. should peak at 5700-5800 or so on those heads. i think its a good grind

if you dont want to put alot of money into the heads, you'll have to keep a stock style cam like a LT1 cam, L98 cam with 1.6 rockers, or one of the RV cams from comp. Those cams are kinda weak but capable of near 350hp on crank so it may fit your bill.

i personally would get your heads machined to handle the extra lift and go with a cam somewhere in the 216-224 intake duration range and get 10 degrees split on the exhaust with a lsa of around 113-114.

z28freak84

Use comp Beehive 918 springs and retainers. They will work awesome with that cam and require NO MACHINE WORK TO INSTALL and by design give you clearance up to .550" lift because of the retainer design. No need to machine the guides for clearance.

Orr89RocZ

iTrader: (20)

really? i have not heard this. what makes it so different than a standard retainer/spring? i know the beehives taper off to a thinner diameter at the top but didnt know they improved clearance as well

z28freak84

its the design of the retainer. Do a search on yahoo....Beehive springs for vortecs or similar wording. Theres a article on carcrafts site that will come up. You can see the difference in height between the two springs and retainers being compared.

Orr89RocZ

iTrader: (20)

awesome good news for sure! thats a nice combination of parts for the price. vortec hsr with vortec heads. with that spring combo, you now can run good cams and not dump money on machining or paying extra for already worked heads. Good deal

85irocz355tpi

Sound like a good deal. I'll tell you about my motor and maybe you'll get a good idea about what you'll be making. I have an 87& later 350 punched out to a 355 with cast crank & rods and dished pistons for my 305 tpi heads. My compression is about 9.5.1. My cam is made by pbm the local speed shop brand. It is a roller with 214deg on Int. and 224 on exh. lift with 1.5 rockers is .470 on int. and .490 on exh. I'm using stock tpi intake with a hypertech thermomaster chip. I'm using flowtech headers and running a custom dual exh. with 40 series flowmasters. Now I don't live in a smog state so the next couple of things you might not get away with but maybe you can. I've ditched the smog pump, cats and anything smog related except what's absolutely necessary to run the tpi. I also ditched the a/c. I gutted the air box and use K&N Filters. I also use delco plugs and oil filters and run Mobil 1 10W30. I'm running a 700R4 with a shift kit and 3.42's in the rear. My internally stock 305 would roast the tires all day long from a dead stop. With the cam I have lost just enough bottom end to take off from a dead stop on good pavement with only tire squeal and when the power kicks in around 2000-2500 It's already going. With this setup my IROC is running mid to high 13's and puts out around 300 Horse at the flywheel. I also want to note even with the chip the car is still running on 305 specs but the maf in my car helps this out. Running 350 computer and injectors along with your intake and heads should definitely give you around 350 Horse. And my cam might actually help you out you can look it up at www.pbmperformance.com I hope this helps.

Ps. Before anyone jumps my s**t about the cats and other smog stuff I removed. It is a commonly practiced thing in my neck of the woods, and with a lack of smog police and tree huggers in the area It will probably remain that way for sometime. On that note I plan to convert my IROC to e85 in the near future and plan on making it pass the sniffer without all that tree hugger crap under my hood.

4playta

Thanks people that was some real good info I am for sure going to look into those beehive springs and I will have screw in studs installed as well.

z28freak84

The beehives are definitely worth it. They cost about 150 for springs a 50 for the retainers. U could do the machine work and get other springs for that, BUT U still have cheap springs and have to wait on machine work. With the beehives, you actually have a pretty kick *** valvetrain and no worries of valve float til 6800 rpm in instead of 6000 rpm.
Good luck. I am doing Vortec with beehives and TITANIUM retainers with a Lunati 232/242 .510/.525" Hydraulic Roller. Texas Speed has their own retainer, titanium, that Way less then the cost of Comps...forget exact price at the moment, but they are considerably less.