I have an 85 Trans Am and i am swapping the bad lg4 305 for a L69 305HO. The L69 came out of an 85 monte carlo SS. I think the exhaust manifolds will swap with no problem, but the guy a bought it off of said that they are probably different bolt patterns. I haven't looked at them this winter because the motor is in storage. Does anyone know if the manifolds i have will work?

------------------
2 - 85 TransAms
http://www.geocities.com/bullfrawgs

[This message has been edited by bullfrawg (edited January 20, 2001).]

 

I'm sure they would have the same bolt pattern. The only thing I can think of that would be different is the size of the ports, but I have no idea if the L69 and the LG4's ports are different for not.

------------------
1989 Pontiac Firebird Formula LO3 Auto
-180 degree stat
-Hooker Cat-Back
**Possible summer '01 mods**
Open Element, Auburn Posi, Keyless Entry, wonder Bar off the IROC, 4th gen seats, T/A tail lights

1985 Camaro IROC-Z LB9 Auto
http://www.geocities.com/krt80/

[This message has been edited by Keith5 (edited January 20, 2001).]

 

I have looked in magazines and the headers you can buy list the same number for all 305s

------------------
1985 TransAm BLK/GLD Stock
1985 TransAm BLK/BLK
305HO (soon as it is put in) 5-speed, 3.27 posi, WS6, power everthing.
http://www.geocities.com/bullfrawgs

 

all smallblocks have the same exaust manifold bolt pattern

 

check that last remark, the 350 vortec heads would not accept my 305 manifolds had I wanted to use them (I did check) as they had one misaligned hole. Headers fit fine on them though F.Y.I.

------------------
91 RS W/carbed 350, Vortec heads, performer rpm, Comp cams Xtreme energy 226/230 duration and .477/.480 lift. BFG Drag radials. 3.42 posi,Corvette servoed 700r4, ****ty stock converter. Edelbrock TES, 3inch cat, flowmaster with single 2.5 inch exit.
13.24@104

 

they should bolt to the heads but what about your Y pipe? Will they interfere with the motor mounts. you need to see how the exaust manifolds' outlets are.

------------------
-Tas
'89 Formula WS-6
[soon to be Torch Red with black hood and headlights =) ]

305, TBI, auto, 14x3 chrome flat based open element with K&N, Milodon 160* thermo, functional Formula hood, cross-flow Flowmaster, '99z28 rear pipes and tips....

Super GRK_Taz World
EFI & Intake Options
AOL IM: superGRtaz
ICQ 82881207

 

He'll be using the LG4 Trans Am's manifolds on the L69 engine. The manifolds are already to the y-pipe in the car.