Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

TPI 305 to 350

Discussion in 'The Garage' started by MTBLAZER89, Nov 6, 2003.

  1. MTBLAZER89

    MTBLAZER89 3/4 ton status Premium Member GMOTM Winner

    Joined:
    Aug 14, 2001
    Posts:
    7,272
    Likes Received:
    236
    Location:
    Oak Harbor, WA
    I know this should be in other rides, but I figured it would get a few more views here. My question is my buddy has an 87 IROC with a 305 in it. He wants to throw a 350 in there and keep his TPI. We have found a few motors for good prices, but they are all older blocks 70's era. What mods need to be done?
    1. Will the TPI manifold bolt to any 350?
    2. Will a new chip be needed for the 350?
    3. Will the sepentine system, and accesories bolt to the older blocks?
    4. Do the heads on the older block need to be changed to later style heads? Will the 305 heads work on a 350?

    Thanks for any info you guys can give /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif
     
  2. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,976
    Likes Received:
    189
    Location:
    Roy WA
    [ QUOTE ]
    Will the TPI manifold bolt to any 350?

    [/ QUOTE ]

    No. Centerbolts are at the wrong angle for earlier motors. Vertical bolts vs. angled. This can be overcome with some grinding. You could also search for an earlier TPI base, as it will have the correct center bolts. Of course you can put the 305 heads on, but see below.

    [ QUOTE ]
    Will a new chip be needed for the 350?


    [/ QUOTE ]

    For best performance, ANY modification to any aspect of the engine/drivetrain/vehicle needs a new chip burned. Yes it will run without being changed, and it may run fine, but you'll be missing some "free" power.

    [ QUOTE ]
    Will the serpentine system, and accesories bolt to the older blocks?


    [/ QUOTE ]

    Yes as long as the heads still have the accessory bolt holes.

    [ QUOTE ]
    Do the heads on the older block need to be changed to later style heads? Will the 305 heads work on a 350?

    [/ QUOTE ]

    The 305 heads will work on a 350, but you up the compression a lot, and the 305 heads aren't that great anyways. 350 heads are the way to go, if you can scrounge up some money , aftermarkets would be the best bet.

    Don't forget the injectors, knock sensor, and ESC will need to be changed.
     
  3. 74beater

    74beater 1/2 ton status

    Joined:
    Sep 20, 2002
    Posts:
    242
    Likes Received:
    0
    Location:
    ELGIN ,TX
    1. NO
    2. YES
    3. YES
    4. PART1 YES PART2 YES BUT WHY? IT,S LIKE RUNNING 1" EXHAUST PIPE
    IT WILL WORK BUT NOT WELL. TELL YOUR BUDDY TO FIND AND 87 OR NEWER IROC GET THE HEADS AND THE CHIP FROM A 350 TPI MOTOR..THROW THOSE 305 HEADS AS FAR AS YOU POSSIBLE CAN.

    ALL HAIL THE ALMIGHTY SAWZALL
    TWISTING DRIVESHAFTS SINCE '00
     
  4. MTBLAZER89

    MTBLAZER89 3/4 ton status Premium Member GMOTM Winner

    Joined:
    Aug 14, 2001
    Posts:
    7,272
    Likes Received:
    236
    Location:
    Oak Harbor, WA
    [ QUOTE ]
    Don't forget the injectors, knock sensor, and ESC will need to be changed

    [/ QUOTE ]

    Care to elaborate on the above topics? Will it just need the bigger injectos for a 350? ESC? electronic spark control?? Can you just replace the module or something? Do older blocks even have a spot for a knock sensor? How can you get around this? Thanks again /forums/images/graemlins/thumb.gif
     
  5. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,976
    Likes Received:
    189
    Location:
    Roy WA
    350 uses the 22lb/hr(? can't remember exact, 305's were 19 IIRC) injectors.
    More if the engine is "hopped up".


    ESC is spark control, there is a module for it mounted(typically) on a bracket with a couple of relays. Square, thin, approx 6-8 pin connector. 350 uses different one than 305.

    Knock sensor threads into the passenger side of the block, just above and forward of the starter. I won't say ALL blocks have this, (it's a threaded hole with a plug in it) as they only made SBC's since 1955, but my '74 block did, and I'd guess at least all 350's and later SBC's have it.

    You'll easily see the plug on a pulled engine, just remember passenger side.
     

Share This Page