Hi Guys,

My old 350 TPI is out of the car and I'm getting ready for the 400 to go in, and just need to know what the sutble differences are that I wouldn't have thought of

The block is 400 2pc rear main seal, have a crank to go in, but after the cost of crack testing, hot wash, linishing/polishing and balancing, it's a lot cheaper to buy a new internally balanced 400 crank I think.
The motor will have AFR1040 eliminator heads, HSR EFI intake and hydraulic cam, 284H or 276H, somewhere around those specs.

So far I've got :

Sump - needs to have US Drivers side dipstick hole (2pc RMS)
Flex plate - needs 153 tooth externally balanced
Balancer - 400 speicifc for externally balanced
Heads - steam holes need to be drilled

Is there anything else, or more info on what sumps I can use, does it need to be a specific shape/type to fit in a 85 firebird?

Will the headers still bolt up in the same place?
Any differences in accessory bolt ups?
Timing chain/set differences?
Engine mounts?
Transmission bolts ups/ torque converter?

If anyone can chime in with any of their experiences or knowledge it will greatly reduce my list of stuff-ups in the process

Thanks.

 

All the same.

It'll use a driver's side dipstick (to the left side as viewed from sitting in the driver's seat), as opposed to the pass side (to the right as viewed from the driver's seat) one that would have come in your car. It will not clear the stock exhaust manifolds.

Headers, as opposed to manifolds, inherently fix that problem, usually. Can't speak to any rhd conversions though.

Any oil pan for 2-pc rear main seal and LH dipstick that will fit any Camaro, Chevelle, or Monte Carlo, will fit your car. Ones that fit trucks, vans, or full-size cars, probably not.

 

Awesome, thanks for that.
Unfortunately, none of those cars were released in Australia, so my only hope is imports or shipping from the states for the sump. I don't think we even had a 400 chev stock in any vehicles here.

With the flex plate and balancer... Can i use the 168tooth flexplate and 350 balancer if I buy an internally balanced 400 crank?

 

Go internally balanced, use a small 350 flex plat and the stock 350 balancer.

I have a nice oil pan from one of my 400 builds. Has a crank scraper and windage screen. PM me if interested.

 

Oh ok, cool.

That would be nice, but I'm in Australia, so shipping usually costs more than the part.

 

When I said "any" oil pan, I meant "any" small block oil pan; not just a 400 one.

My favorite one has always been the old "Z28" pan, that came on the 350 in the early 70s Z28s. I think it's discontinued now though. But ANY pan that fits Camaro, Monte Carlo, or Chevelle, will fit your car.

I agree w using the small flex plate; lets the starter sit closer to the crank, which leaves more clearance to the exhaust and everything else. You probably will have to get the inboard bolt hole drilled into your block for it though, as that style starter didn't appear until about 78 or so, and most 400s are older than that; and the factory notoriously didn't install any "features from the future" in most things. Any competent machine shop should be able to drill the hole.



This is a 400 block I drilled the hole in some years ago.

 

Will this pan be fine?
http://www.ebay.com.au/itm/Chevy-SBC...item23400f86fd

 

Should be.

 

Actually, I don't think that will fit... looks like a truck/full-size pan. Note how wide & square the front is.

Compare to this one. http://paceperformance.com/i-6536345...y-engines.html This is the "Z28" pan.

Compare also to this one, which will fit the chassis, but of course, not a 400. https://sdparts.com/details/gm-facto...parts/12557558 Provides a good point of reference though.

 

That pan should fit. The third gens don't have a lot of limiting factors when it comes to oil pans. I run a summit 7 qt kicked out sump pan on my 355 in my '88 camaro.