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capev86 · 02-16-2010, 08:39 PM

the 400 was an awesome engine. only problem is most came equipped with a 2 barrel which seriously limited performance potential. if you are rebuilding one, be sure to have (or have machined) cross drilling in both the block and the cylinder heads to compensate for the siamese cylinders that don't have water jackets for cooling. the 2 bolt engine block is stronger at the bottom end.

my dad put a 406sbc in his 84 burb back in the mid 90's for trailer towing. the truck was a 2wd with 3.73 gear and overdrive and he swapped the q-jet and manifold over from the original 350 and kept the restrictive exhaust for practicality sake. it still ran awesome and got 16+mpg without retuning the carb. the only problem was the engine was a '77 model year and had leftover heads with a cross drilled block. towing our trailer on a test run cracked the heads. with the proper cross drilled cylinder heads installed the engine performed beautifully on a month long trip out to Yellowstone and back. the burb went like an over sized camaro and was tons of fun on solo runs. we pulled a few years back when my dad junked his (rusty) truck and saved for a project......which turns out to be my 72 burb 3/4 ton with 3 speed column manual and (soon to be) 4.10 gear swap.

the 307 in my truck (and 327) have a 3-1/4" stroke, the 305/350 have the more desirable 3-1/2" stroke and the 400 has a 3-3/4" stroke. if i didn't have my 406 and my 72 burb had a lot more than 74,000 miles i'd put a 400 crank in that 307 and build a good economy stump puller. the 383 is another good example of power with economy. there is a company out there that is building wide skirt small block's that use a special 4" stroker crank (and very big pistons) and you can get a vintage style small block chevy punched out to 472 cubic inches.....ouch!!

02-16-2010, 08:39 PM	#14
capev86 Registered User Join Date: May 2009 Location: Eliot, Maine Posts: 1,314	Re: Stock 1972 sbc 400 specs? the 400 was an awesome engine. only problem is most came equipped with a 2 barrel which seriously limited performance potential. if you are rebuilding one, be sure to have (or have machined) cross drilling in both the block and the cylinder heads to compensate for the siamese cylinders that don't have water jackets for cooling. the 2 bolt engine block is stronger at the bottom end. my dad put a 406sbc in his 84 burb back in the mid 90's for trailer towing. the truck was a 2wd with 3.73 gear and overdrive and he swapped the q-jet and manifold over from the original 350 and kept the restrictive exhaust for practicality sake. it still ran awesome and got 16+mpg without retuning the carb. the only problem was the engine was a '77 model year and had leftover heads with a cross drilled block. towing our trailer on a test run cracked the heads. with the proper cross drilled cylinder heads installed the engine performed beautifully on a month long trip out to Yellowstone and back. the burb went like an over sized camaro and was tons of fun on solo runs. we pulled a few years back when my dad junked his (rusty) truck and saved for a project......which turns out to be my 72 burb 3/4 ton with 3 speed column manual and (soon to be) 4.10 gear swap. the 307 in my truck (and 327) have a 3-1/4" stroke, the 305/350 have the more desirable 3-1/2" stroke and the 400 has a 3-3/4" stroke. if i didn't have my 406 and my 72 burb had a lot more than 74,000 miles i'd put a 400 crank in that 307 and build a good economy stump puller. the 383 is another good example of power with economy. there is a company out there that is building wide skirt small block's that use a special 4" stroker crank (and very big pistons) and you can get a vintage style small block chevy punched out to 472 cubic inches.....ouch!!