253 conversion.

[peterderrin]

Does a 253 place too much stress on V6 running gear-ie: the origional trimatic box and diff?

[ZSANDY]

A 253 would have less power than most newer V6's so no . But I think you might have meant a holden straight six ?? In short a 253 would take a lot of work to bolt to a six cylinder trans and the standard six diff wouldn't take much abuse before braking . Although most Holden utes and vans post HQ ran the same diffs for V8's and 6's with different ratio's to suit the application .

[ozbox]

peter,to do a v8 conversion with a 253 or 308 carb motor there is a couple of things that are different...for the point of me explaining here we will stick with a 253 as its simpler...

ok..to put a 253 in where a six was we need...startin at the front..
a v8 radiator or get the necks changed to the v8 positioniong as they are different for the hoses..
a 253 complete with engine mount brackets and sump and pick up and either the v8 trimatic or the v8 4 speed that was behind the motor to start with that way we get all the v8 stuff...has to be from any hq through to wb...

we dont get a v8 and auto from a vb to vl commodore..ok..:knockout:

the engine mounts on the chassis of the car is the same six or eight..your gearbox crossmember is the same six or eight..your speedo cable is the same six or eight..
you can leave the six cylinder tailshaft and differential in the car as the lenghths dont change..
but if you do that you need to not be doing burnouts as it will go bang at either the axle or the pinnion of the diff and in extreme cases the universal of the tailshaft..

hope this answers the question in some detail and if you need to know more please just post up in this thread..this goes for all reading..

please note what is explained here is only for a 253 and trimatic or aussie 4 speed..can also be used with 308 but the block must be tri matic or 4 speed pattern..not turbo as everything from back of motor changes...

[ozbox]

and to go one step further....

the reason i said dont get a motor from a commodore is that to make it fit an hq to wb you will have to change..which meens buying which meens more money than first thought...
alternator bracket
crank pulley
water pump coz commodore is a long shaft
sump and pick up
engine mount to block plates coz if you dont do thes the motor sits in the wrong position.
also commodore gearbox as in autos is left hand side shifter only...

[Mazdragon]

thanks for the info. Useful for me too in some ways.
However, I want to convert from std 6 (202) to a 308, straight gas. Would i use the same considerations as u've described for the 253? i'm guessing i'd have to do something about the suspension as it's a lot heavier? and figuring the diff would need changing? not sure what's in there, Beigy is stock std so my guess is whatever they came out with. I'm also wanting to do the mild cam thingo, nothing too radical, just a good rythm and sound. I'd like to keep it a manual (currently 3 on tree), and am thinkg of going 4 or even 5 speed manual, but hav peeps telling me that I should go auto instead. Any ideas, advice? I'll be removing the petrol totally and putting in a second gas tank, the dizzy's going to be set up for gas too, as well as the heads and of course the cam. I don't understand a heap about modifying, so am fishing for info at the mo.
Will be grateful for any feedback.
thanks
Maz

[ozbox]

maz,beigy will have a diff thats commonly refered to as a small 10 bolt..beigy is wb correct?.
the gears in a small 10 bolt are the same as a banjo but fine spline axles..no burnouts and no major acceloration and it will hold up..your tailshaft is already a v8 configuration as all wb came like that...so all else is as i have stated..whern you get to it if you need any advice just call...or send pics...:Chin: