i have a few questions on my car. it has the 700r4 transmission i know that for sure. but i have no clue what the rear is. i see it has a 9 bolt rear. what is that and what gear ratio is that

 

A 9 bolt rear is the "heavy duty" rear axle for these cars as opposed to the standard 10 bolt rear. Its a fairly rare Australian built axle I thought was only used behind motors like the l69, l98, and some lb9s. Gear ratio depends probably easiest to look it up on your RPO codes assuming its original.

 

i think the engine that was in here was the 350 tpi even though when i look at the rear i see it has drum brakes even though i was wishing for it to be all ws6

 

no drum brakes on a 9 bolt

is there a rubber fill plug on the diff cover?

89 with a 9 bolt would be 4 wheel disc brakes


the 8th digit of the vin will tell you the motor the car was built with.

 

a real 350 tpi car 8th digit is a 8

 

im not sure the 8th number is an E which is a 305(anybody know where i can get a tune port injection intake manifold?). i count 9 bolts on the rear and i see drum brakes. not sure what this means. how do i find the RPO codes for this?

 

Rears are not named for the number of bolts that hold the cover on.

Vin code E is a TBI 305 engine, like your sig reads. None of the 305 TBI cars came with rear disk brakes that I know of, and as said, all "9 bolts" had rear disk brakes.

Why ask about a TPI intake when you have a TBI car?

 

well i know that about the rears. i called the guy who had the car before me he told me that the rear end that was originally on there was a 10 bolt rear but he had it to low to the ground and when he took it to store it at his friends house on the path there is all these rocks and he hit one really hard and smashed it all up(god only knows how fast he was going) he told me him and his friend bought a 9 bolt rear out of a something he dont remember what it was(he did it 2 years ago) and put it on there.

the 305 tbi cars did come with 4 wheel discs.. the formula's did but mine is not a formula.

i asked about a tpi intake because i was going to do a swap so instead of getting a lousy 170 hp i will get 210 and then throw a cai on and get another "25-30 hp"

 

i think the guy you got the car from is full of ****

you wont get 210 hp from a tpi intake on a 305 tbi motor,the tbi motor has a different cam and heads.

base model formula's dont get 4 wheel disc.only the tpi cars

 

i think he is too because he told me there was 20 dollars in gas in it and the tank was bone dry and he said he had a brand new headliner for it and when i picked it up this thing looked like ****. 4 wheel disc was base on formulas and formula 350's i know this for a fact because 6 years ago my dad had bought an 89 formula 305 tbi and we checked it out it had ws6 suspension with 4 wheel disc brakes.

 

89 is 20+ years old - someone probabnly swapped in the WS6 and rear discs before your dad bought it.

As mentioned, to get the extra horses, you'll have to swap the whole TPI system over, which includes a new wiring harness, the TPI heads, cam, exhaust, intake, etc. You'd much easier and cheaper do a 350 TBI swap from a wrecked truck or Caprice - just keep all your TBI stuff, swap in a 350, add 350 injectors, 350 knock sensor, and 350 chip.

 

truck 350 with headers


factory 4 wheel disc on tpi cars only ,someone swaped it in,9 bolts are disc and have a rubber fill plug on the diff cover.

 

i found out that ws6 was all the way back in the 70's it was only on trans ams not firebirds or formulas that was all the way up till 85 anything 86 and newer had 4 wheel disc on base formulas and trans ams. that wrap around spoiler was introduced and the regular spoiler(like on mine) was put on standard firebirds instead of just the trans am's. the 350 swap makes no sense. if i keep the smaller engine and swap to tpi i need exhaust but if i do 350 i dont. hmm luckily i have a set of headers that fits the 5.0 and the 5.7 liter that i been wanting to put on for a while now. but i might do a 350 swap.

what other than the engine its self would i need i dont think i need new wiring if i do keep the tbi system. so what else would i need to do this

 

I have a formula, I don't have rear disc brakes...

 

Here's the ratios that came in the f-body 9 bolt rears- 2.77, 3.27, and 3.45. The lousy 2.77 ratio is most common of course, followed by 3.27. 3.45 was quite rare as it only came in 5 speed manual equipped 305 TPI cars with the G92 performance package. To find out what ratio you have, you'll either have to jack up the car, rotate the tire 1 full revolution while counting how many times your yoke turns, or take off the rearend cover and look on the outer surface of the ring gear or the back of the pinion gear. The ratio is usually stamped on either the ring gear or the back or the pinion, or sometimes on both. If there's a set of numbers divided by a colon stamped on there, all you do is divide the bigger number by the smaller one to figure the ratio. Ex. 12:41=3.42.

 

go look at my albums i just uploaded pics of what my dads car looked like. his was just like this and he had 4 wheel discs it was all original he bought his for 10500 it had low miles and a year later we threw a 350 in her and kept it tbi. yours might say formula.. hell when i look up the car fax for mine it says formula but i know a formula from a base and mine is not a formula. all they came with was the wrap around spoiler and the bulge turbo hood and ws6 suspension. and a base firebird had the flat hood and the regular gay spoiler like i have.

 

yeah mine has the wraparound spoiler, the bulge hood as you referred to it ... the suspension is WS6, because I had trouble once with bushing not fitting... could be a possibility that the rear was changed, but then again I do have front and rear wheels... I don't know... the RPO code label I could not find, I've tried compnine.com to look for it but their servers haven't been updated to fill my request...

 

you never know what people have done to these cars before we buy them. i was going to replace my brake yesterday but i dont have the lug nut lock for the wheels and i seen the PO had spray painted the tires black to make them look brand new again.