I have an 89 trans am that came with the 305, I was wondering what i would need to drop a 350 Chevy into it? Thanks

 

Nothing...

If one gen 1 sbc fits, they all will. So 1958 to 1992 car and up to 2002 truck/van/suv with gen 1 style engine will drop right in.

Thats the 262, 265, 267, 283, 302, 305, 307, 327, 350, 400

Now some changes was made to heads, acc. brackets, oil pans, intakes, etc over that 44 year span, so you have to look at that and keep that in mind.

Here is a list of some of the changes

1955 1st chevy small block 265 cid
1956 Oil filter mounting pad added
1957 283 introduced, 283 HP with mech. FI, removed rear grooved cam bearing from block
1958 Side engine mounts added
1959 Rope seal replaced by 2 pc rubber rear main seal
1960 1st factory alum. Heads introduced (recalled because of porosity probs)
1961 283 makes 315 HP with mech. FI
1962 327 introduced
1964 1st 2.02”/1.60” valve heads, 327 fuelie makes 375 HP
1965 Last year for mech. FI
1966 327/350 HP engine introduced with hyd. Cam
1967 Last year for 283, 1st year for 302 and 350. 350 introduces larger journal sizes
1968 All small blocks go to larger journals, temp sender from intake to head
1969 Last year for 302, 1st year for long water pump, all heads gets acc. Mounting holes
1970 400 sb introduced, LT1 350 makes 370 HP in corvette
1971 Compression ratio drops due to emission regs.
1972 Last year for solid cams and holley carbs in hi-po engines
1974 HEI ignition introduced
1976 305 introduced
1979 Oil dipstick moves from driver to pass side
1980 Last year for 400, 1st year for computer controlled system
1981 Crossfire injection introduced
1985 Tuned port injection introduced
1986 Major changes.. Center bolt valve covers, new oil pan flange, 1 pc rear seal. 3.58” dis. Flywheel flange changed to 3.00”
1987 Intake center bolt angle changed from 90* to 73*.. L98 alum vette heads keeps 90*, hyd roller cam provisions added
1992 Gen II engine introduced.. LT1 350
1996 Vortec truck engine introduced with high flow heads, roller cam, plastic timing cover, 8 intake bolts.. Gen II LT4 hits 330 HP with roller rockers, high flow alum heads
1997 LS1 installed in corvette
1998 LS1 installed in F body


Heads…
1969 and up got acc. Mounting holes
1955-59 have staggered valve cover mount pattern
Temp sender moved to head in 1967
Starting in 1970 all 2.02/1.60 heads got screw in rocker studs

Flywheel, flexplate, starter, damper
153 tooth 12.75” od
168 tooth 14” od
1955-68 dampers have timing mark 2* before keyway center line
1969 and up dampers have timing marks 10* before keyway centerline

 

Wow, I'm bookmarking this... Thx for the history

 

Your welcome

 

To "drop it in", true.

To get it running right - depends upon the induction on your 305.

TPI - not much, since '89 TPI was a mass air flow system, although larger injectors (like the factory did) would help at full power.

TBI - It's a speed density system, which is sensitive to changes such as displacement, exhaust flow, etc. Tuning will be required.