From:  (Eric Youngblood)
Newsgroups: alt.autos.rod-n-custom
Subject: Re: 1978 T/A questions
Date: 16 Nov 92 21:46:00 GMT
Reply-To: Peon w/o Email priv (Eric Youngblood)
Organization: Bell-Northern Research, Richardson, Tx

In article <Nov15.092759.60538@yuma.ACNS.ColoState.EDU>, pattons@CS.ColoState.EDU (samuel patton) writes:
|> I have a 1978 Trans Am with the W72 Pontiac 400 and M21 tranny.  It is 
|> relatively stock but does have headers on it already.
|> 
|> Has anyone out there rebuilt a 400 for high performance using unleaded gas?
|> If so any tips on good books concerning the engine and how to tackle this 
|> task would be great... 
|> 
|> 
|> I also need to rehang the drivers side door since it sags.  How do you go about
|> doing this???? Is it hard or not... I would like to avoid paying someone to 
|> do this...
|> 
|> 

Hey Sam,

I have the same engine in my 77 TA.  I built it to run well on the street but with
alot more scoot.

I put a mild performance street cam (272 (214@.050)int / 282(224@.050) exh), 
.447 inch int & .465 inch exh lift. I run 9.2:1 compression on unleaded gas, forged aluminum TRW pistons, Holley 650 vac sec, ~36" length 1-5/8 in dia headers,
dual exhaust w/ cross over. Stock intake manifold under a K&N air filter & open hood scoop.                   ^^^^^^^^^^^^^^^^
                              (non-EGR equipt)                                  
    
This combination is very well behaved and damn near no hassle. Idle vacumm 
is about 17".  The engine had the mains line honed and the entire crank assembly
was balanced. All tolerances are blueprinted.

This combination produces about 275hp@5000 and 365 lbft tq @3000. I did not have 
the heads ported as pontiac heads are not "High-Flow" design. The stock heads
provide rapid flow below about .3" lift but, can really benefit from more duration
and lifts above .4 inch.  The D-port exhaust heads force the exhaust flow to make
an immediate 135 degree downward turn to acheive that "under the plug" exhaust
port. Because of this pontiac heads will flow better with about 10 deg more dur.
exhaust timing as well with additional lift.

This engine is mated to a performance built TH350 (Stock converter for gas mileage
reasons).  This one of the major factors that went into cam selection.  The car
does 6.3 0-60 mph & 14.68 1/4 @ 104mph. limiting factors are the 3.08 std rear
axle and Goodyear P235 60 R15 STs and intake manifold which favors low end
torque. 
 
With a manual tranny you will be able to choose more duration and a higher lift
profile cam. A decent performance manifold will buy you good power also. A good
positraction 3.23 will help your launch but allow you to cruise *some* too.

A set of P265 50 R15's will fit stock 8" rims (some ballooning) but will keep
the ride height the same without any steering or suspension problems. A set-up
like this should easily be able to acheive ~5.5 to 5.8 0-60mph times and do
1/4 mile in the low 14's. 
 
As far as those damn sagging doors:

A. Use a hydralic bottle jack to support the door while you loosen the hinge 
   bolts. pump the jack a bit and re-tighten.

B. Use the bumper jack to raise the body. support the door with wood or something
   and lower the body a bit. then re-tighten the hinge bolts.


Hope this helped,

$0.02
Ericy
Newsgroups: alt.autos.rod-n-custom