i ENDED WITH A 350 LONGBLOCK OFF OF A 1971 CHEVY C10 CHEYENE AND AM PLANNING PUTTING IN MY 84 T/A which currently has 305 5.0 ho...do i need to do any modifications like i was told maybe the tranny housing or something along those lines...ca na ny one help enlighten me

 

Do you have an automatic or standard transmission?

 

I have a 1984 trans am that HAD a 305 h.o and a T5. My friend gave me his 78 vette 350 and i swapped it in, nothing needs to be changed it is a direct fit, i would suggest new motor mounts and other basic maintenance that are easy to replace while the motor is out because it will save you a lot of headache down the road.

 

An older block may not have the holes already drilled to mount the starter for the T5's flywheel.

 

im pretty sure all blocks from 70 to 81 were identical on the outside. 71 is a great year becuase it is still higher compression and dosnt have any of the smog stuff on it

 

Wrong on all counts.

Dimensionally identical, but differences in details such as dipstick location, holes drilled, etc.

Truck engines have low compression.

Smog equipment is part of the car, not the engine.

 

I agree however in the mid to late 70's egr and other emissions equipment were implemented, smaller carburetors and restrictive manifolds were also used to help reduce emissions and conserve fuel. All the way up to 72 or 73 are the most powerful stock. I belive they had a higher compression ratio to run leaded fuels which were still around in the early 70's

 

Not true. Early 70's truck engines had small port, small valve, large chamber heads, and dished pistons.

daddy - You don't need to make any modification to the bell housing. As stated, though, if you have a 5-speed, you may have starter mounting issues - you need to check that out before you get too involved in the swap (the good news is your flexplate or flywheel will fit the older engine). The dip stick being on the driver side is a real hassle if you try to use 3rd gen factory exhaust manifolds - headers (typically a good idea, anyway) takes care of that problem.

The really bad news is if you have the 305 HO, and it runs like it should, it will have just as much (and maybe more) power than a stock '71 truck 350. Oh, that year 350 also didn't have hardened valves or valve seats for unleaded gasoline. Personally, I wouldn't consider this unless the 350 got different heads, new pistons, a cam that will pull beyond 4500 RPMs, and I knew for sure my starter would bolt up to the block.

 

It's easy enough to have the starter bolt hole drilled and tapped while the engine is out, if it's missing and you need it.

There's always the option of a shortblock swap to overcome low compression, using the HO heads on the 350.

Then again, we don't even know if this 71 engine is an all-original, tired-out 40 year-old dog, or if it's been rebuilt at some point.

 

Sorry about that i was getting all of my information from a 70 camaro book and then i just realized "HEY ITS A TRUCK BLOCK" lol, although the compression is lower, it should have around the same power, but i think the truck motors had more torque which is better for the street, also the 350 has far more potential than the 305.

 

i do have a stick tranny... but the thing is i only bought the motor bcuz the guy i bought it off of was going to do the swap with me but he lagged it for more than a week just to take out the motor out of his truck....so im gunna have trouble with the starter? and the the 305 in it is stuck since it sat for more than 10 years and id rather have a 350 for the potential

 

as for the motor its never been rebuilt according to the guy i bought it off of he bought the truck off of an old man who bought it new in 71 and always maintained it well...it only had 185k miles (on a 71) it sounded good when i heard it run..yeah i would have bought something newer ifi new i was going to run into problems but i was going to pay for the whole swap with 550 buck plus miscellaneous parts and gaskets and stuff

 

For a '71, 85k miles was long-in-the-tooth, let alone 185k miles. See the reference to "hardened valves and seats" above.

Since your 305 is seized up, okay, at least this 350 will get the car moving on its own power again. But, be aware of what you've been told above. This guy might think he's got everything covered, then discover he can't mount the starter and you won't see your car for another couple of months. Or he hands you the keys in one hand and the dipstick in the other - "I couldn't figure out how to get this in, guess you'll have to change the oil often so you know how much is in it."

 

185K! time for a rebuild

 

i took the car and the motor elsewhere but i took some headers (shortys) from him for the cost of the wasted tow they were on that truck but dont kno if theyll fit my t/a... if they do fit will that solve the dipstick problem?

 

If they fit, that'll take care of the dipstick interference problem.

 

Truck headers won't even come close to fitting a thirdgen.