Danlee;

Thank you for clarifying the point with respect to the crankshaft throw; I must revisit my sources and determine what I misinterpreted so as not to make the same error again.

Please pardon my ignorance, but how interchangeable are these parts assuming the 351m and 400 had the same cylinder bore ? I have been planning a future re-build and have been gathering up an inventory of parts. I have a complete 400 in okay shape that was going to be a donor unit as needs dictated, however I hadn't made any final decisions about pistons, crankshaft etc. until the 351m had been torn down and assessed.

My objective is to achieve a higher revving engine based on the smaller displacement 351m to maximize top end speed and fuel economy as my use is 100% highway, rather than off road use where low end torque is more desireable.

I understand there are very few after market choices for 351m pistons, only 1 manufacturer if I recall. Beyond that, I thought there was a fair degree of flexibility to mix and match, so to speak.

Would you have any suggestions or an opinion with respect to the best combination or mix of these components, if any, given my stated objective ?Assume there are no sacred cows to be mindful of (....please resist any temptation to suggest I abandon the idea and buy something new or drop a 350 Chebby in as a Hyundai Pony driving buddy once remarked !)

I have given a lot of thought to going with a 302 just for the availability of parts, but my small budget doesn't allow for many exotics in any case. Must haves include a mild cam, new intake and 4 bbl carb, exhaust and doing what is necessary to the block. If my 351m needs a lot of remedial treatment, I would likely re-think the project from scratch.

Its hard to keep it all in perspective when I can pick up a running 302 or 351m/400 for between $150 - $250 Canadian dollars. Neither of these gets me any farther down the road than where I am today, other than I have a good idea of whats under my hood now.

Maybe I need to approach "She who must be obeyed" for an increase in my allowance, seeing as Christmas and birthday presents are socks and ties now that I'm well into my fifties.....

Thanks for your input.
JT

 

JT,

Swaping in a 302 will cost more in parts than rebuilding a 351M/400.

It should cost no more to build it as a 400, than a 351M because the only difference are the crank and pistons.

A 400 will give you more torque and horsepower than a 351M, but it will not give you fuel economy. Your best bet for power and fuel economy at highway speeds is a set of Aussie heads and 351M low compression replacement pistons and a Comp Cams 265DEH cam with a 351M crank. You may need to use mid-grade or premium grade fuel, depending on your final compression ratio. You would like to end up no higher than 9.5:1 CR.

 

I'll be changing my 351m to a 400 but the crank and pistons are an additional expense- Well..not really the pistons as I'd have to swap them anyhow to get more compression.. The cams seem a bit pricier too.

It's just that from all I hear the 400 is Well Worth It.

 

also- mvtofino- that is a hell of a story- I had similar experience as a kid with my pinto and my '57 f100 with 292. My oldest son has run his toyota 22r near out of oil several times and can't seem to kill it- if anyone can kill a rig it's him. It's like there is a car god.

 

Danlee;

Very encouraging information. I've read a little about Aussie heads, but have no idea about availability here in Canada. I would imagine related miscellaneous conversion costs like mounts, tranny change, etc. would be where the 302 would eat up the bucks.

Thank you for sharing such specialized knowledge with us.

JT

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Roger:

There is a noticeable difference between almost out of oil and an engine compartment with no trace of an oil related particle. What prevented a melt down is beyond me !
I didn't recognize your the model of your son's Toyota, but the 3 I've had ('78 Landruiser Short Wheelbase w/350 Chevy conversion; '81 Landcruiser Short Wheelbase Diesel; '90 4Runner 4 Dr. V-6) were tough and reliable units. The 78 with the 350 could pull a medium sized hospital off its foundation - but a manual wheelchair had a better top end.

Good luck with your 351/400 project. Be sure to post your progress so we can learn from the experience......

JT

 

You can buy ausie heads off the internet right now but at $800 I'm not jumping on it yet. The 22r toyota was the motor in his little truck.