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Hi Everyone,

It seems that I am having a crisis of conscious (sp?) about whether to convert my 86 efi to carb.

My plans for the car are street/strip. Something to run around in on the nicer weekend days and run at the strip two or three times a month and at a couple of Fun Ford events. I am concerned with driveability and need to pass emissions (Houston, Harris County). It needs to be capable of a 300 or 400 mile drive, and the AC must work. Gas mileage is not that big of a deal, but I don't want single digits.

My plans are to pull the motor and rebuild to a 331. Decent heads, cam, exhaust, etc. It is an AOD car with 3.73s. I would like to see low 13s (maybe high 12s ;)) on pump gas (93 octane is ok).

My budget is around $3000 and that must pay for the stroker, too. A buddy and I will handle the labor. Would you convert to carb or stay EFI considering the above info? I would greatly appreciate any and all comments/experiences/opinions. Thanks!
 

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well when you said pass emissions you answered your own question keep it injected. i don't know what texas emissions are like but here in IL> we have the dyno testing and car between i belive 79 and 95 have to be tesed on the dyno and pass an idle test and a cruseing speed test . would be harder to pass that with the carb setup but not impossible .
 

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First and foremost, the '86 four eyed cars rule!

Second, you don't need a 331 CID engine to run in the low 13's with your 'vert. I think you would be crazy to stick a carb on an '86. The '86 model year is the only four-eyed car to offer SEFI. Besides, I've seen too many white trash, '87-up cars that were completely hacked because someone wanted to go carb'd. If you do a carb, at least do a clean install.

Rebuild the current '86 shortblock with your stock crank and rods. Buy some .030" over pistons. Re-use your stock cam and install 1.7 roller rockers. Get a GT-40 or equivalent intake and GT-40p's/ported E7TE's/Twisted Wedge heads. Get a 65mm throttle body (I believe your '86 has a wimpy 58 mm t/body.) With your 3.73's, an exhaust, an aftermarket torque convertor, and traction your in the low 13's and meeting emissions to boot.

The stroker kit would be an easy $1,000 in parts alone. Machining your block and balancing the assembly is another $800. You've just blown two-thirds of you budget on the internals of your engine. You still need to buy the intake, injectors, mass-air meter conversion, bigger camshaft, throttle body, and fuel pump that the 331 is going to want. Unless you can get a good deal on used parts, I don't think you can do a 331 for $3,000 bucks. Maybe if you doubled your budget. Especially when you add up all the nickel and dime parts like gaskets, bearings, head bolts, main cap studs or bolts, harmonic balancer, t/stat, coolant hoses, etc.

If you stay with a 306 and stock cam, you should be able to keep the speed density set-up and avoid the expense of a larger cam, injectors, and fuel pump that a 331 stroker would want.

If your 302 is in good health then install some of the bolt-ons and put your car on a diet. Do the stroker when you have more money.
 

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that was some good advise . i only llooked at the emissions aspect of it but you can deffinitly get into the 13's on the motor in your car if it's healthy . just remeber you have tru flat tops and no cam shaft swaps will be able to be done unless you have the pistons notched for valve relifs. but you can do a heads and intake swap and a 65mm throttle body exhaust and a converter and go 13's no problem and pass smog i'd step up the gears to 410's as well but thats me .
 

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Discussion Starter #5
BP Convt said:
First and foremost, the '86 four eyed cars rule!

Second, you don't need a 331 CID engine to run in the low 13's with your 'vert. I think you would be crazy to stick a carb on an '86. The '86 model year is the only four-eyed car to offer SEFI. Besides, I've seen too many white trash, '87-up cars that were completely hacked because someone wanted to go carb'd. If you do a carb, at least do a clean install.
Absolutely!! I have seen those too. A clean install is a must! I happen to be quite anal, so when she is all done, you will be able to eat off of the engine!!

Rebuild the current '86 shortblock with your stock crank and rods. Buy some .030" over pistons. Re-use your stock cam and install 1.7 roller rockers. Get a GT-40 or equivalent intake and GT-40p's/ported E7TE's/Twisted Wedge heads. Get a 65mm throttle body (I believe your '86 has a wimpy 58 mm t/body.) With your 3.73's, an exhaust, an aftermarket torque convertor, and traction your in the low 13's and meeting emissions to boot.
Forgive the ignorance here, but the block will need to be bored .030" over for that, right? And, since I need to replace the pistons, I am guessing I should get some forged with valve reliefs? I like the TW and AFR 165 heads. :)

The stroker kit would be an easy $1,000 in parts alone. Machining your block and balancing the assembly is another $800. You've just blown two-thirds of you budget on the internals of your engine. You still need to buy the intake, injectors, mass-air meter conversion, bigger camshaft, throttle body, and fuel pump that the 331 is going to want. Unless you can get a good deal on used parts, I don't think you can do a 331 for $3,000 bucks. Maybe if you doubled your budget. Especially when you add up all the nickel and dime parts like gaskets, bearings, head bolts, main cap studs or bolts, harmonic balancer, t/stat, coolant hoses, etc.
That was mainly because I was thinking low 13s need the extra cubic inches since I don't want to spin the motor to 6800 rpm for a good track time. After looking at the expense, a stroker is out of the question.

If you stay with a 306 and stock cam, you should be able to keep the speed density set-up and avoid the expense of a larger cam, injectors, and fuel pump that a 331 stroker would want.

If your 302 is in good health then install some of the bolt-ons and put your car on a diet. Do the stroker when you have more money.
Awesome! I really appreciate the advice. I do have one other question, though. Heads: AFR or TW? and Intake recommendations? Thanks again! :) :cool:
 

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My vote is to stick wilth EFI also...

My vote would also be to stick with the EFI. You can pass emissions and meet your goal. There are several people running 12s (like nojuice) with a '86 shortblock with either ported E7 heads or aftermarkets.

Not that my daily-driver is fast enough for you, but with the listed bolt-ons it's an easy high 13s car with some sticky tires. If it were a weekend-warrior, I think I could get it in the 12s no problem with about $1000. (4.10s, full exhaust, slicks, etc.)

Can't answer your AFR/TF head question, but if you upgrade your upper intake and TB (yes, the '86 has the wimpy 58mm) to '87+ parts and do some mild porting / gasket matching, it's a cheap alternative and a good match for your stock cam.

Good luck! Mark
 

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Just a thought, having done a carbed 331(450hp at the flywheel) and sold it. Now having done my current combo which I highly recommend:
#1 Freshen up your stock engine, and buy a set of gt-40p's (or home port stock heads) and a used aftermarket intake- $1,300 to $1,500
#2 Buy a vortech s/c trim ($1600 or so) and a 7" crank pulley from ASP......

There you have it- low 13's or high 12's- completely daily drivable!!

I don't know what my car will run et wise(it spins bad) but it does go 107mph in the 1/4. I'm running a BONE STOCK 97K mile 5.0 with a vortech A-trim out of the box- 88 GT/5-sp.

I love it, it drives like stock and goes pretty good.....the only down fall is boost is an addiction! I've already got bigger injectors, bigger mass air, 7" crank pulley, BTM, power pipe, etc...already waiting for spring!
 

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my '86 GT recipie:

TFS twisted wedge heads
stock cam with 1.7 rockers retarded 4*
TFS street intake.

or, you could go carb'd... run the TW heads with a decent cam/intake/carb.

I would lean towards EFI as Texas is getting stricter on emissions laws.

I would NOT recomend building a stoker or even building a 306. you have the best factory pistons in your engine, and if your block will take a hone, there's no logical reason to bore it.

you'll be supprised how UN-far $3k goes when messing with this stuff... your heads and intake will be close to half that!

use the rest of the money to get a Tremec in there!

Forrest
 

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don't mess w/ the P heads... get the twisted wedges... they'll blow the P heads away and they'll work with your factory pistons... you should be at ~9.5:1 compression w/ box stock TW's w/ your pistons! :D

Forrest
 

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HeyMoe said:
You've got flat top pistons, careful on the valve clearance if you dont put new pistons in.
again, trick flows don't utilize the stock valve notches... they will work with a flat top piston with no reliefs the same as they'll work on a stock piston with stock valve reliefs, they'll just have higher compression

Forrest
 
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