89formula#1

hey guys i am lookin to build up my 305 in my 89 formula wiuth a 5spd. i have a tbi right now and i and wondering if switchin the carb with make a big diff. i am lookin to put the vortec head son with a performer intake and a nice cam. my question is what are u guys runnin with your 305 carb engines? thanks

five7kid

iTrader: (14)

At the risk of starting another flame war with the Vortec Loyalists...

Forget the Vortecs.

Especially on a 305. Get some real 305 heads like I did. Spend the money you'll save not doing the Vortec conversion on other things that will actually make you faster.

I don't have post-mod times yet, but my best stock time was 16.85 at 5800' elevation (that's 15.6's corrected to sea level). I expect to be in the low 15's at 5800' when the track opens in April, which would translate to low-14's at sea level. That's emissions-legal with highway gears and 14" street tires (eat your heart out, CHP Mag).

84L69TA

Im running 15.11 @ 90mph with my stock 305 engine. Look at the mods in my sig to see what I have done to it.

86SCBNJ

I'm not up on NJ emissions testing, but if you switch to a carb, you will fail the visual part (if there is one)... It just gets more complicalted from there... Can someone from Nj verify what the testing procdures are???

toosloz

my car has seen many mid 14 sec runs....all i added was a new carb and intake

edelbrock 1406 600cfm
performer intake
stock vac advance hei



my motor was a L-69 so that might make a difference...i bet with heads and a new cam i could have hit 13s no prob:lala:

Sparkee

I wouldn't bother with the Vortecs on a 305. The stock 305 heads can be made to flow respectible numbers with a little porting and a good valve job. If you need to pass emissions, I would stick with the TBI. If you remove it, you will have to swap distributors as well, and will have some misc electrical problems.

I would go with overhauling your stock heads or maybe go with the World Products S/R torquer 305 heads, Edelbrock Performer TBI manifold and an aftermarket TB unit, like Holley. I'm pretty sure they are all CARB approved replacements, but you might want to verify that. A new cam would help a bunch, too. Your open element air filter has more Hp than stock, but you can do better with a cold air induction. The open filters flow more air, but they just suck hot air from around the engine.

Stock, you should be in the low-mid 15's, depending on altitude and weather. With the intake and TB alone, maybe mid-upper14's. With cam and heads, low-mid 14's. With all these mods, something better on the air cleaner and 3.73's, you might hit the 13's. Good luck.

checkeye

13.5@103.99
vortec heads
XE274H cam
650 Holley DP
check the flow charts, then decide.

89formula#1

hey checkeye is that on a 305? and what do u have done to it? wjat are your cam specs?

x5finger

World Products S/R Torquer 305
.400 = I 198 E 156
.500 = I 213 E 166

Vortec
.400 = I 227 E 151
.500 = I 239 E 160

checkeye

'86 305 w/ 140+ miles
Performer intake
TES headers 3" exhaust

comp cam XE274H
advertised I 274 E 286 @.050 I 230 E 236 I .486 E .490

Scoggin/dickey sells a kit for the swap
http://www.sdpc2000.com/cart.asp?act...d=277&pid=1120

Depends where you wanna go with the motor. If you're keeping it under 6K RPM you can't beat the vortecs for the money.
If you're looking to make 400HP or more, then you'd be better off with more expensive heads that can be ported and will eventually flow better numbers.

That cam is about the highest lift you can do with stock vortecs. I've been running them for a year or so, have made 20+ passes and have had no problems.

Did not mill the heads, just bolted everything on.

89formula#1

wait u said your cams a 230/236 dur. @50 ?? isn't that to big for a 305?? is it a roller?

checkeye

that's what Comp Cams has listed in their catalog.

No it's a hydraulic lifter.

It works fine, I had a XE256H in it before
256/268
212/218 @ .050"
.447/.454
with this cam and stock CC carb it ran 14.5's @ 99.79 MPH

The 274 works much better, mid range torque is great, pulls hard up to 6K and has a little lump at idle. Still pulls around 12" vacuum at idle.

Tom84L69

I run ported L69 heads with the cam in the sig. My best bet is high 13s, I've beaten several LS1s and any stock new mustang.

I've heard nothing but good stuff about vortecs but I'll vouch that the L69 heads can be made to flow well.

By the way, my car has no computer, and the cam sounds great and pulls past 6 grand.

89formula#1

hey tom are u runnin a 305??? also isn't a 230 duration cam to big for a 305?? and the 108 lobe seperation?? i heard stay above 12 and now more then 220 duration with a 305. wut other mods do u have and wut suspension work?

Tom84L69

yeah it's a 305, the original L69. The bottom end is rebuilt with the original pistons, new rings and bearings. I ported the stock heads and milled them for 10:1 compression. I have crane pusrods, some stiffer valvesprings and a ported factory aluminum intake. I have a Qjet but not the original computer controlled unit. In fact, the car has no emissions equipment or computer, who needs it? I have headers w/ dynomax 2 1/2 pipe and flowmaster muffler w/ no cat.

I talked to a well respected engine builder friend before i built it and he said the cam would be fine but not if I were to drive it every day. It is not good for fuel economy but it is the greatest improvement i have made to the car. I bet it wouldn't work with a computer though.

my cam in a 350 would act milder than it does in my 305, that's the way it is.

My suspension is bone stock save for an energy suspension trans mount. It came with a T5 and factory 3.73 posi. I do have 255/60/15 tires on the original rims for better traction. It launched hard till the axle and tranny stopped working!!!