hey boys, my plan to rebuild my 350 fell through, so now i have about 500-700 bux to spend this winter. i have an 86 Iroc wiht 45000 miles, headers, cat back, and shift kit. i just ran a compression test and had 165psi on all holes. i want to install a cam, and i also have a set of 3.73 gears on my bench at home. should i put the gears in? i think i am gonna run a XE256H-12 cam from comp cams, what else should i get? i am just lookin for suggestions. what would u guys do?

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86 IROC
43,000 miles
305/700R4/3.23 gears
maroon, gold stickers, black interior, T-Tops.

current mods.
shift kit
headers
cat back exhaust

mods planned for this winter
cam
Adjustable fuel pressure regulator
port and polish intake and heads
lookin to run low 14s maybe squeak out a 13.9 with my stock chip

 

Definetly put in the gears esp. 3:73's Def go for the cam, and if you have some money left over, intake could be a good suggestion, dont forget the little mods ie: plugs, wires, car +rotor, etc. the little things ad up but intake and cam ull b seeing a diffrence

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1988 Camaro Iroc-z
305 ci Tuned Port 700R4
3" Exhaust/Flowmaster 80 series muffler/Dynomax high flo cat
hypertech chip/k&n filters
Cut out MAF screens
TPIS Airfoil
"Camaros RULE!!"
"Theres no replacement for displacement"
SAVE THE F-BODY!!!!

 

From what I can see you have more than enough money to add a set of Vortec heads to your 305, about $450. The cam you are considering is just right for those heads

Get the Vortecs that will accept your regular style intake bolt pattern (there are two types) and you will be looking at a tidy little 50 horsepower increase!

 

I'm assuming you have TPI. If so, then don't go with the 3:73s because the stock TPI stops breathing past 4500rpms. Unless you have modified the TPI, go with 3:42s, but since you have 3:23s, I would go with the above mention of getting heads and cam.

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2 Tickets to game= $250
Gas= $20
Sitting 20ft. from MJ= Priceless
'86 IROC T-TOPS, TINTED WINDOWS, BRAKE LIGHT BLACKOUTS
GM GOODWRENCH 350
EDELBROCK HEADERS Hooker CatBack
EDELBROCK 600CFM CARB.
KN AIRFILTER
ACCEL HEI DISTRIBUTOR
160* Stat, just switched to 180* b/c of winter coming and going to college in the mts.
3:73 Posi Rebuilt 700R4
B&M Megashifter, 5" Autometer Tach w/shift lite

 

I agree with Mark, spend your money on heads and a cam before gears. This is assuming that you have tpi. If you get vortecs and a cam you will see a huge improvement. I hear the 86 LB9 cam was pretty weak.

Good luck

 

yah i do have TPI, and yah the peanut cam is pathetic. i will look into the vortec heads. my dad works at a GM dealership and can get stuff at 10% over dealer cost. that sounds like a good way to go. any other suggestions. the rest of u guys think it is a good idea?

 

hey guys i have some questions about these vortec heads. with 64cc chambers, wont my compression go down? what heads will fit my intake? do i need special rockers? i am still lookin for info, but it would be cool if u guys could help me out.

 

Your TPI intake won't bolt up to Vortec heads. There is no such thing as Vortecs that will accept a TPI intake. It's not a question of just the bolt holes; the ports are in the wrong place. Scoggin-Dickey has started seeling a lower intake with the right port location and all for Vortecs, but it isn't cheap. You're certainly not going to get heads, cam, and lower, plus all the misc that you invariably need when doing a head swap, for $700. That would be an easy $1000 by the time it was actually done.

That would be a good cam. IMHO as long as you keep the stock TPI on a 305, changing the heads is a rather low bang-for-the-buck proposition. Port and polish your 416s, especially the bowls right behind the valves and the "short side" radiuses, and you'll mostly eliminate them as a bottleneck.

I see no problem with upgrading the gears. You won't believe the difference. 3.73s do not particularly require the engine to run higher than 4500 RPM.

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"So many Mustangs, so little time..."
ICON Motorsports

 

Obvisouly you have more knowledge about cars than me, so don't think I'm trying to argue with you. But I've always heard people say stay away from 3:73s with stock TPI. Wouldn't he run out of power in the 1/4 with those gears. He would probably be pushing over 5k rpms. And with the stock TPI he wouldn't be in his power band, that's why I thought he should go with 3:42s.

[This message has been edited by Mark A Shields (edited November 27, 2001).]

 

I know you carb boys get a real improvement with 3.73's, but I have seen people gain .1-.2 with 3.73's on tpi motors. Its just not worth it when you think about how much drivability/gas mileage you loose. Or maybe I should say, the money is better spent elsewhere. Someone told me about these phantom Vortecs being made that will accept tpi, but I have no proof of their existance. If those are out of the question then the World Torquer 305's have done very well in performance tests (with slight bowl work) and run under $700 for the pair assembled. Like RB83L69 said, porting the stock heads can give you some real good gains. Just be SURE to change the cam

 

Mark is right about the gears: 3.73 with TPI is a big no-no. I sure wish someone had told me that before I put them in. Now I'm overgeared and screaming redline when I go through the traps. Besides, with a 700R4, that first gear ratio (3.06:1 or something) is such a monster that you're not exactly at a loss for torque there. And the cost of going from 3.23 to 3.42 is not worth it. If you had a 2.73 it would be, but not for 3.23. You're best bet would probably be to go with working over your stock heads and matching up a cam to them.

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91 Z28
Come see The Vicious...

 

I have a question: Wouldn't a TPI motor have a roller cam and isn't the cam he listed a flat tappet hydraulic? Im guessing Im out in left field on this one cuz nobody else asked this. Just wondering.

 

For an 86 that cam is fine, they started going with roller in 87.

 

I think alot of the gear controversy has to do with the expectations for the car's usage, as much as what it actually does for the car's performance. I come from a rather long history of driving performance cars with 3.73 gears; Chevelle SS396s, 60s & 70s Z28s, etc. all had them stock; one of my Z28s (I think it was a 79 4-speed car) broke its rear end once and I went to the boneyard and all they had was one with 4.10s in it, and believe it or not, that was noticeably peppier than the 3.73s. But even at that, I have a carbed car, that came from the factory with 3.73s, so it does have some top end, and it almost never crosses beyond 4500 RPM during normal driving even though it still pulls well past that. It just isn't necessary most of the time.

On a TPI car, it's probably true that the step up in gears won't make as much of a difference in ¼ mile ET as it would in a car with a motor that could breathe. However, most of us drive around town alot more than we do on the strip; and for stoplight-to-stoplight punch, nothing else comes close to gears for the amount of immediate, SOTP improvement you get, for what they cost. I've seen it way too many times. And for this guy, he already has the gears, all it will cost him is the $100 kit, a couple of quarts of fluid, and an afternoon. What a deal.

One of the biggest improvements I have made to a car recently by doing that was to go from 2.73s to 3.42s in my 74 454/400 Caprice convertible. It felt like adding 125 cubic inches, literally. The gas mileage is only slightly worse on the highway (before, the converter was stalled driving down the road at 55 anyway, now it's at least above the stall RPM) and it's better around town, plus the car is almost fun to drive instead of feeling like a sluggish lead sled with the motor always sounding like it's straining just to move the car at all.

And you're right, he has the flat-tappet version of the peanut cam, rollers strted the next year, so that is a good cam choice.

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"So many Mustangs, so little time..."
ICON Motorsports

 

hey guys, thanks alot for all the help. i am definetly gonna pull the heads, take em apart and clean the carbon off, smooth the bowls and short sides of the ports, and port match the intake runners. i will prolly just lap the valves in by hand, and be done wiht the heads. i also am going to port the plenum, and port match teh rest of the intake. i can get a good deal on a TPI gasket set from GM, but i was told they are too small, and if i was gonna port match, i should get some from Accel. is that true? i am also still on the fence about the cam i want to run. so i will list em here and you guys vote in teh one u think is best, remember i am runnin the stock chip for now.

1 crane 2030 204/214 .423/.446 110LSA
2 crane 2032 210/216 .440/.454 114LSA
3 compcams 206/212 .434/.444 112LSA
4 compcams 212/218 .449/.456 112LSA

i just cant seem to decide what cam i want to run. so tell me what u guys think.

i am still on the fence about the gears, but i may run them. lower gears give any engine a mechanical advantage, regardless of where it is ran. at lower speeds on the street they may make a difference, but i am unsure how much difference i will feel going from 3.23 to 3.73. it is roughly a 15% gear reduction.

[This message has been edited by 1MeanZ (edited November 27, 2001).]

 

Cam #2 if you change the gears, #3 if you keep your 3.23s

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"So many Mustangs, so little time..."
ICON Motorsports

 

The L69 cam WAS NOT the same as the dreaded "Peanut" cam!

The L69 had .404 and .415 lift specs.

The LG4 "Goodwrench" (Peanut) cam sported an unbelievable .350 and .385 lift.

Great low end torque but no hp above 4000 rpm

 

Sitting Bull,
Been hitting the peace pipe lately? No one said anything about L69 cams.