Downdraft

1965 Convertible 327/300

If I replace my 300 hp smallblock with a 600hp + 434 small block what else must be upgraded? I am in the process of installing a complete suspension kit (VBP) and have included adjustable strut rods.

I am running 235/70-15 on 8 inch rims (flaired fenders)

Can my stock U joints and rear end bracket handle the extra power - or will I start breaking things?

Would I be able to get the 600+ Hp to perform on the vert or should I go for a more "tame" 475-500 HP 383?

See the dyno sheet of the Steve Schmidt 434

434 cu. in. Pro "Street Series" Dyno Chart

RPM-----------------C TORQ---------------C PWR
BAND---------------FT - LB------------------CHP

4900------------------568.3--------------------535.5
5000------------------568.3--------------------541.1
5100------------------566.8--------------------550.3
5200------------------564.1--------------------558.5
5300------------------567.5--------------------572.7
5400------------------564.6--------------------580.5
5500------------------561.0--------------------587.5
5600------------------552.9--------------------589.5
5700------------------548.4--------------------595.2
5800------------------537.8--------------------594.0
5900------------------536.2--------------------602.4
6000------------------531.2--------------------606.8
6100------------------525.2--------------------610.0
6200------------------518.4--------------------612.0
6300------------------511.7--------------------613.8
6400------------------508.0--------------------619.0
6500------------------498.8--------------------617.3
6600------------------493.1--------------------619.7
6700------------------479.3--------------------611.4
MAX TORQUE------568.3
MAX HORSEPOWER------------------------619.7

Thanks.

Alex

ZYALTR

Alex, these drive trains have handled 400+ hp for a lot of years. That said ...if you throw 600hp and tourque at it on a regular basis be prepared for component failure. Things break.

66since71

There may be some benefit in using big block yokes and companion flanges (they use caps instead of u-bolts) at either end of the half shafts. Also later C-3 drive shafts used larger U-joints and should (?) fit a C-2. Edit: That will require changing the input yoke to the rear end though. Finally the M-22 transmission has straighter cut gears to handle more torque.

MasterDave

Just keep the stock size tires and the only thing you will break will be traction.....

JohnZ

If you go with bigger tires without significantly upgrading the half-shafts, you'll get this eventually:

kenEDMUNDS

Ouch!

67L36Driver

or a normal duty clutch. You got to have a weak link thats cheap to fix.

LouieM

My all-time favorite of JohnZ's many photos!

R6T7

Hey John -

How much horsepower was this car running?? Great pictures -

Bob

427Hotrod

They hold fine if the frame is solid. A little re-inforcing can't hurt either!!


JIM

mjmsc5

You would think you could get a couple of inches of clearance with the front tires. You just aren't trying hard enough

tdelph

I have a convertible that can handle 600+ HP but you have to upgrade the rest of the drivetrain to handle it. A small block 600hp vette could be a little more uncivilized than a comparable BB...good luck

427Hotrod

Yeah,,,,,that was bad,,,,,he got some of the GOOD ones with big air showing but they were too fuzzy to use in magazine. I never could get him to let me have them!


But I'll try harder at the Cruise In this year!!

JIM

JohnZ

That was a 540 Merlin with 8" slicks. You can make a mess with stock tires too - note the twist in these half-shafts (Jerry Luck-built L-89 with stock tires), found just in time: