GrumpyBadger

Hey all,

Since I haven't even bought my Trans Am yet I figure I can enjoy some "armchair greasemonkeying" in trying to figure out the right 305 I want and the VIN that goes with it when I check out the cars.

Basically, I'm looking for the ones with the hydraulic-roller camshaft. And yeah, since it's a 305 I've had a heck of a time finding much besides:
http://www.transamworld.com/3genvins.php
within that we have this:
1982-1984
H = 305 ci V8 LG4 (1982-1984)
7 = 305 ci V8 LU5 (1982), L69 (1983)
S = 305 ci V8 LU5 TBI (1983)
G = 305 ci V8 L69 HO (1984)

1985-1986
F = 305 ci V8 LB9 (1985-1986)
G = 305 ci V8 L69 HO w/MT (1985-1986)

1987-1992
F = 305 ci V8 LB9 (1987-1992)
H = 305 ci V8 LG4 (1987)
E = 305 ci V8 L03 (1988-1992

and this, from Wikipedia of all places, it was easy to read
Chevrolet 305 V8 [RPO LG4]: Overhead valves. Cast-iron block. Displacement: 306 cid. Bore & stroke: 3.74 x 3.48 in. Compression ratio: (8.6:1: 1982-84), (9.5:1: 1985-87). Brake horsepower: (145: 1982), (150: 1983-84), (155: 1986) @ 4000 rpm, (160: 1985), (155: 1987) @ 4200 rpm. Torque: 240 ft/lbs @ (2000 rpm: 1982), (2400 rpm: 1983-84), (250 @ 2400 rpm: 1985), (235–245 ft/lbs @ 2000-2400 rpm: 1986-87). Hydraulic valve lifters. Carburetion: 4-barrel (Rochester E4ME: 1983-87). (EFI: 1983-84). VIN Code: H. (Standard in Trans Am. Optional in base Firebird and Firebird S/E: 1986), (Standard with 5-speed manual transmission in base Firebird V8, Formula and Trans Am: 1987).

Chevrolet H.O. 305 V8 [RPO L69] (Late 1983 - Early 86): Overhead valves. Cast-iron block. Displacement: 306 cid. Bore & stroke: 3.74 x 3.48 in. Compression ratio: 9.5:1. Brake horsepower: 190 @ 4800 rpm. Torque: 240 ft/lbs @ 3200 rpm. Hydraulic valve lifters. Carburetor: 4-barrel. VIN Code: G and was a Trans Am Only Option. Came Standard on the Y84 1984 Recaro Edition Trans Am SE and 1984 15th Anniversary T/A

Chevrolet V8 [RPO LB9] (1985–87) Overhead valves. Cast-iron block. Displacement: 306 cid. Bore & stroke: 3.74 x 3.48 in. Compression ratio: 9.5:1. Brake horsepower: (205: 1985-86), (165: 1987) @ 4400 rpm. Torque: (275 ft/lbs @ 3200 rpm: 1985-86), (235 ft/lbs @ 2000 rpm: 1987). Hydraulic valve lifters. Induction: (Electronic tuned port fuel injection: 1985-86), (Multi-port fuel injection: 1987). VIN Code: (F: 1985-86), (8: 1987). (Optional in Trans Am only: 1986), (Available with 5-speed manual transmission in Formula or Trans Am. Available as a delete option in the Trans Am GTA: 1987).

Chevrolet 305 V8 [RPO LU5] (1982–84): Overhead valves. Cast-iron block. Displacement: 306 cid. Bore & stroke: 3.74 x 3.48 in. Compression ratio: 9.5:1. Brake horsepower: (165: 1982), (175: 1983) @ 4200 rpm, (190 @ 4800 rpm: 1984). Torque: 240 ft/lbs @ (2400 rpm: 1982, 3200 rpm: 1984), (250 ft/lbs @ 2800 rpm: 1983). Hydraulic valve lifters. (Induction: Crossfire fuel injection (EFI): 1982-83). (Carburetion: 4-barrel: 1984). VIN Code: (7: 1982-83), (G: 1984).

it looks to be 1986-1990 would be good years for me. I'm just not really a fan of the late third-gen Firebirds with the airbags and bumpers, but I'd like TPI to begin with.

any help on which RPO codes and VIN codes are the good ones? It'd be greatly appreciated. I really enjoy the 305/5spd cars.

1991sleeper

iTrader: (-3)

I think hydraulic roller cams are from 1987 and up Mine is a 91' and it has HR

eseibel67

If you want 305 -TPI - 5 speed - no ugly airbag in the steering wheel, you want an 87-89.

RPO code for engine: LB9
RPO code for trans: MK6

GrumpyBadger

I'm also wondering what the casting numbers would be for the right 305s?
yeah, I'm going nuts.

But it's okay, I'm just used to doing this to verify Shelbys, Hemis, and Yenkos... not a 3rd gen F-body. But to me, this is my dream car, just as much as my cousin finding his Shelby at the swap meet under a tarp... so I want to get it right.

I gotta ask you guys, since you're both 305 guys too, but with different rear-end final gears. What's your RPM at 75? And what height tires do you have? I'm thinking a 275/45-18 on mine, or the stock wheel size if I'm not allowed the low-pro, but I'm pretty sure it is in my class I want to race in. Ironically sub-frame connectors are a huge deal, but low-profile tires and shock/spring choice... aren't!

eseibel67

Partial VIN is stamped on the block deck in front of the head - passenger side bank.

If it's an 88-89, it's tough to see behind the A/C compressor. If the block was decked during a rebuild, of course it would have been ground off.

GrumpyBadger

Thanks eseibel67,

it's good to know some things don't change lol. That's a good call about the stamp being ground off too, a good way to tell if it's had a rebuild or whoever's car I'm checking out is blowing possible moonshine up my tailpipe!

blakbird89

Get a GTA with a T-5!

eseibel67

Sorry, I cannot tell you because I am stuck inside for the long cold winter.

But I can tell you the MK6 transmission has a .73 ratio in 5th, which in conjuction with the 3.45 axle ratio, makes it quite a good performer at highway speed. No need to downshift if you want to get moving, just step on the gas.

With the excellent torque these TPI 305's make, a .5 ratio 6th gear would be an excellent fuel saver for long distance highway cruising.

1991sleeper

iTrader: (-3)

My 91' with rebuilt 305 TBI T-5 trans and 4.10 gears pulls about 2500RPM at 70mph with 26" tires I'm putting 28" tires on it when these are
Wore out

GrumpyBadger

I hear ya bud. I may live in Arizona, but I'm in a mountain, and we had snow this past week and below freezing starting two weeks ago.

at least you have a sexy beast in your garage right? Your armchair greasemonkeying has to be better on a laptop in the garage in the driver seat with AC/DC or Tom Petty playing on cassette

yeah, those RPMs sound great in general. I'm still getting used to 4 gears with an OD. My Elky had a 400 in her... with 4.10s

luvofjah

iTrader: (2)

Keep in mind, that with 90 and up cars the TPI used MAP, not MAF as previously used. The 305 for the later years, the five-speeds that got the hot cam, were the third most powerful engines in these cars just behind a 5.7 TPI of those years and of course the turbo Trans Am of 1989 with the v6 .

eseibel67

^ Yes, most powerful 3rd gen production engines were 3.8 turbo and 5.7 TPI. Unfortunately, enjoyment of either was minimized due to mandatory 4 speed automatic transmission.

If you actually like driving, best 3rd gen configuration was 5.0 liter, 5 speed manual transmission and proper gear ratio. Either L69 HO Q-jet with 3.73, or later TPI with 9-bolt 3.45 or 10-bolt 3.42.

GrumpyBadger

so, what exactly is the difference, "nitty-gritty", between a MAP and a MAF... that's a good point, because obviously they went back to the MAF

as far as I'm concerned, though about the "third most powerful" that can be debated, at least with the 5.7. Auto trannies, especially early 700R4 eat a lot of power, let alone with their stock torque converters. It's why I stuck with a TH400 in my Elky. I didn't like what I saw, and I also had a 50/50 shot of it blowing up the first time at the track, no matter how "built" it was or what builders could claim... a downed car is a downed car, no matter for how long

I think the 5.0/5spd is the best combination, especially with the WS6, or 1LE for a stock 3rd gen out there. I gotta agree with eseibel67... but I'm also a more "turning" kind of guy now anyways. For me, and me alone, not preaching, after I went under that vaulted 10 sec time, I lost the "hook." Playing at Willow Springs or Laguna, that never has gotten old. I blame my buddy's "replica" 1969 z28 for that. She's a 302 with T56 and 4.11s or something maybe even shorter, with 5-speed close. 5th is 1:1. SWEET freaking car. Looks bone stock on the outside too. And no worries, she was a 6 cylinder car when he bought her!

although...
salt flats, 200mph... yeah, that's still nerving me

now if we're talking "sleepers" it's easy to build a 500tq/hp "small block" with a TKO mean 5 speed behind it. Can't tell on the outside if it's a 305 or 350 or even a 427... do that with super quiet exhaust but with some "on the fly" cutouts... yeap, super sleeper that even a new 2014 Z28 would have a hard time handling.

luvofjah

iTrader: (2)

Stock and quickest... the 90-92 305, 5 speeds with a hot cam are only two tenths of a second slower than a 5.7 TPI cars.

GrumpyBadger

Not going to lie, here's my idea of a build:
LB9
stock block and heads
blueprinted and balanced short block
port and polish the heads and intake... maybe even stock cam ...
headers and exhaust though can be whatever I want
I think, think I may be able to do a different intake too...
but the cam specs, heads, and such need to be within "accordance to manual and rebuild specifications for original"
however... if it's ANY head available...
I wonder if that means ANY head available from GM at the time, or just for that specific engine? if it's ANY available in the "catalog" lol L98 could be nice, but worried about the big valves.
SCCA rules make it a wee-bit of a pain lol

beyond that, if I jump a class:
LB9
same bottom end
Vortec heads
LT4 hotcam
Edelbrock Pro-FloXT intake (I'm an Eddy guy)

or...
4" stroke 4.125" bore Dart
235cc AFRs
Comp Cams custom ground to it, and my car's rear-end gear ratio and tire size, and NOT as extreme as I had in my Elky that was .7" lift/solid... yeah, not going there again!
mean aftermarket TPI on top

what do you guys think? This is for autox, hillclimbs, and track days btw

RockinGTA89

sounds like a pretty good setup for a 305. It just depends what the rules are for what you planning to do with your car.
I've always wanted to make a road racer. At one point when i had my 87 TA i was thinking of turning it into a racer 305 and max it out, but then the rear end blew up. Gave up on that and got a 89 GTA.
Here's a few comparison that i've driven:
I owned and drove a 87 Trans Am. It was a 305TPI (LB9) with the 700R4 and 2.73 gears.
it was slow, is all i can say, but at the time i didn't care for much about speed...
until i got into a my 89 GTA. That was a much stronger car with the TPI L98 350, with the 700R4 and 3.27 gears. Chirp the tires on lauch from 1st to 2nd and 2nd to 3rd at times...still the 700R4 was the downfall as it was kinda dragging the vehicle's potential, acceleration wise. However i was able to do a 14.3 in my GTA at a drag strip in stock trim, only had rear lower control arms replaced with aftermarket ones and adjustable struts and shocks with front end wonderbar on stock tires.

The one car i thought that changed my mind was driving my uncle's 85 Iroc L69 305 car.
It had the 305 4bbl, 5spd, and 3.73 gears. Wow that was a pretty fast car in stock trim is all i can say! I swear this car could of kept with my GTA if i was able to get it run side by side.

So in my opinion, giving the right circumstances if you can hop a 305. I'm sure they car be pretty good moving motors. I've heard about the SCCA regulations about what you can do and can't do with mods. I always wondered if is allowed to use the SLP stuff on these engines as they were legal components for stock engines into putting out more power? Anyone?

iaxbird

Just a quick question:
I recently picked up an 83 Daytona 500 edition trans am for like 400 bucks, I'm pretty stoked on it but have a ton of work to do to get it running. The crossfire injection has been a pain in my *** for the past 2 weeks now, i was wondering if i would be able to do a straight swap with a tuned port system without a tremendous amount of further *** pains. Anyone have any advice? From what i understand the CFI was not the best anyways so if i could trade it for a tuned port or any other injection system i would be VERY VERY happy!
Also what heads could i swap the LU5 heads for that'll give me some decent results that aren't crazy aftermarket? Vortec? TPI? Etc..
Thanks guys! hope to hear something before i lose all my hair from stress!
-Ino

KITT1983

iTrader: (3)

What 1.6 ratio rocker arms work great for the 83 crossfire injection 305 ?

1991sleeper

iTrader: (-3)

I used cheapo summit brand on my 91 LO3 .. just slapped em in didn't check nothing except preload .. ran good for 30k miles till I took motor out n was still going strong with 220k on it

91' bird 305 TBI T-5, trick flow heads, 4.10 gears, full UMI setup, track times coming soon!

1991sleeper

iTrader: (-3)

I used cheapo summit brand on my 91 LO3 .. just slapped em in didn't check nothing except preload .. ran good for 30k miles till I took motor out n was still going strong with 220k on it

91' bird 305 TBI T-5, trick flow heads, 4.10 gears, full UMI setup, track times coming soon!

KITT1983

iTrader: (3)

Awesome
Did you get any lower gains from the rocker arms? Do you have a link to them?