If anybody read my post in General Tech, I recently blew my engine. I overreved it (shifted into 2nd going approx 100mph) , and my cad died. My entire top end is all fine. The problem is on the bottom end, so obviously I either need to repair or replace.
The 350 I have in there is a 68 casting. Now I my question is:

Can I use the 305cid bottom end from my parts 86 TA, I figure everything should bolt right up and should get me around until I can rebuild the 350 (this is my only driver). My only concern is will the tranny pattern on the 86 block match my transmission (700R4 not sure of the year)?

Can anybody point me towards a good book on how to swap engines? I know the basics but never actually did it and will need as much guidance as possible. Thanks everybody...

Dazed and confused,
-Max

 

Flexplate will be diffrent. I ordered a 350 one on accident from summit, when i got a new tranny for my 305....

That's about all i know though!

hope i helped,

 

The bellhousing bolt pattern did not change on Chevy V8's from 1955 to well into the 90's. As stated, the flexplate will be different since your current engine is '85-older, but the '86 piece will bolt to the converter (assuming the '86 engine has a flexplate on it).

Why aren't you using the entire 305 engine? 350 heads on a 305 is a receipe for low compression. Besides, how do you know the top end is all fine? Over-reving typically takes out a rocker, valve, spring, pushrod, or some multiple of those. I'd check it all over very carefully if I were you.

This isn't so much a swap as it is a replacement. The common Haynes manual should have enough info to at least get you on the right path.

 

The '86 crank, being a one piece rear main seal piece, physically won't fit into your older 2-piece rear main seal block.

You can buy an adapter to go the other way (2-piece RMS crank into a 1-piece RMS block) but that doesn't help in your case.

 

I don't know what I was writing in the beginning, obviously I am not going to use the 350 heads and will stick with the stock 305 ones. Anyways the TC I have should bolt onto the 305 flexplate.
Now I have a couple of more questions fro you experts:

How about motormount locations? Will they be the same.

My current setup has a mechanical fuel pump, will I be able to reuse it with the 305 (since 305 was TPI originally, will it have a provision for a mechanical FP)?

One last thing. The intake I have on the 350 has the same bolt pattern as the 86 heads, correct?

Thanks you very much everybody, I really appreciate your help, and I can begin to see the positive in this situation now:
While the 305 is in there, I am building me a nice 383 :hail: (hopefully my hurt block is ok)

 

Why would I need to fit my 86 crank into the 68 block. I am swapping complete engines. Block, crank, rods, pistons, and heads. Thanks fro the help anyways.

 

The motor mount locations will be the same, and the 86 will have a provision for the fuel pump, it will be blocked off though. you will need to reuse your fuel pump rod as well. The intake will bolt up just fine as well. When you originally posted, it sounded like you were planning on running the stock bottom end with the 350 top end, thats why all the confusing questions

 

If your '68 block is still in good shape, Dan Burk has a 383 rotating assembly complete with coated pistons for sale, $200.

 

I am planning to run a 305 bottom end with a 350 top end as sort of a stopgap until I can build the 350 to my liking.

About my 68, I don't know if its still ok, I will ahve to tear it down first to see, btu can you please get me in touch with this Dan Burk guy, I would be very interested in that provided the stuff is in good shape.

Also about the mech. fuel pump provision, Is it bolted shut, can I open it up and how much of a hassle is it trying to put that rod in. Becasue if it's too much it will be easier to wire up the electric one thats attached to the back of the car (was saving it for a nitrous system but that will have to be delayed)

Thanks everybody, I will begin on the 305 today and please keep the posts coming.

-Max

 

Dan's email from yesterday:

<font face="Courier New">I have a newly reconditioned 383 cast crank(for 2pc rear main seal)
laying around, along with a set of 5.565" rods and some TRW forged
.030-over pistons. The crank is externally balanced and comes with a
stock 400 damper and flexplate. The journals are machined down to
-.010"/-.010" on 350 mains. The pistons have been coated with Techline
coating's ceramic thermal barrier.

I'm selling the whole lot for $200. Anyone interested?</font>

<A HREF="https://www.thirdgen.org/techbb2/member.php?s=&action=getinfo&userid=531">View</A> his profile or email him at <A HREF="mailto:dan@ws6transam.org">dan@ws6transam.org</A>

 

When you say bottom end, what do you mean? Bootom end usually refers to block and evrything internal. top end is heads, valvetrain. the intake system is just that, the intake. So if you plan on running the 305 motor withe 350 intake, youll be fine. if you plan on actually swapping the heads off your 350 to the 305, your gonna be running a brick. As for the mechanical fuel pump, the cover is just four bolts, pop them off(you may have to pry it off once the bolts are out) and with a new gasket, the fuel pump is almost ready. The fuel pump rod is no big deal. any auto parts store should have a new one if you dont want to fish out your old one. just make sure the pump lever goes against it, not on top of it, kinda hard to do, but there should be some tension when you are tightening the pump down. as for bottom end damage, what exactly happened after the over rev?did it start knocking or just losing power? if you didnt have bottom end noise, just a slug of a motor, i would pull the heads with motor still in the car and have THEM checked out. If you are running a high lift cam, you may have kissed, but you may have gotten away with a few bad lifters, bent pushrods and a few broken springs. just something to look into before downgrading and going through all that work.
mike.
if you have any more questions, feel free to email me
petrifink@msn.com

 

Thanks guys,

Sorry for the wrong terminology, I am using the 305 (heads and valvetrain inlcuded) with the 350 intake. I changed a mechanical fuel pump before, so if all I have to do is pop off 4 bolts, thats no prob. I took the car to a shop when it broke hoping that it would be a busted valvespring or something minor. They did a compression test, pulled the valvecovers and told me the whole valvetrain is still good (don't know how they chacked the valves without pulling the heads though). I will look at it myself when I get her home.

I am not sure if I had bottom end noise, the car just stalled on me after I overrevved it and would still start but as soon as I let off the gas it would slowly die.

afgun: Thanks for the info, now can anybody tell me what years of 350's came with 2 piece rear main seal (prior to 85?)

Thanks for the help everybody, my car is coming back on Monday and I will take a look at what's wrong myslef then.

 

Any smallblock Chevy '85 and older is 2-piece rear main seal design. The design change was implemented in '86.

For reference, bottom end in engine building terminology refers to the crank and rods, not the block. Top end is the piston and wrist pin. May mean different things to different people but check with your machinist if you disagree.

 

Sounds to me like you need to check into your "blown" motor a little more.Does the motor still turn over? Are there any holes in the block? It could just be a broken timing chain and some bent valves/pushrods. I accidentally over revved my 57 Chevy(350hp/327) once, floated the valves and broke the timing chain.It backfired once and died.New chain and one new valve and back on the road.

 

Well, I am planning to go down to the shop tmorrow and discuss what they did tomorrow. I don't want to speculate but I have a feeling that the problem is in the valve-train, so I am going to pull the heads and the timing cover tomorrow and see what's up there. Thanks for the help, I'll let everybody know how everything turns out.

P.S. I don't think my timing chain broke because the car still ran (very bad, but it ran) afterwards, but it may have slipped a couple of teeth. Can anybody tell me how to see if my cahin slipped a couple of teeth?

Thanks,
-Max

 

You can check your ign timing. If it's all the sudden way retarded, the timing chain probably slipped a tooth.