Took a look under the car today because of a few issues n found out I have some (3 to be exact) teeth missing on the flex plate . Now I kno I only have two options; pull the engine to get to it or pull the tranny. Tranny is a much easier job but it's still got the whimpy 305 in it, so yup it's coming out. ample opportunity to make the jump to the deep end and get a 350. So I kno I'm going to get yelled at about how's there's a thousand post on this . But I need help with more than just the basic swap Q n A and y'all prolly not doing anything better so c'mon help me out lol. Ok so here we go. I have a 1987 firebird with I believe is the original carbureted 305. I want to swap to a 350 carbed. I already have edelbrock ; performer intake, 600cfm (1406) carb , chrome n black centerbolt valve covers and a performance coil. I want to transfer all of those along with most the other stock assessories on the front of the engine to the 350. I'm prolly also going to keep the heads off the 305 (I here this is a good idea) but get it ported polished and ad new pushrods and rocker arms. So I pretty much just need a 350 block with pistons and crankshaft and a aftermarket camshaft and lifters to match the 305 heads right? I'm looking to spend in the 1000-1500 dollar range. I've never rebuild a bottom end before but I'm pretty mechanically inclined so I think i can manage plus I have friends that are savvy and can help. But for what I'm trying to spend can I get a short block already put together for about the same price and save myself the hassle? Even with the set up(305 stock heads ) I want to accomplish? If not and I need to slap a bottom end together myself what pistons, cam and lifters do I need to use for a match with the 305 heads? And for the swap itself what new wire adapters will I need if any or any other parts I'll need to match the new 350? Do I need a new knock sensor? I kno what it does but have no clue what it looks like or where it's at on the engine. Also since my carb won't be computer controlled do I need to worry about a new ECM or anything to that effect? This isn't and won't b my daily driver and I'm not worried about passing emissions or inspection. I'm pretty stuck on my 1000-1500 price range for this engine swap as well. I appreciate any and all help . Thanks in advance

 

If all you REALLY want to accomplish is just change out the flex plate, you don't have to pull ANYTHING to do that. (well, nothing "big", anyway...)

Unbolt the 3 converter bolts. Support the trans and remove the crossmember and drive shaft. Remove the 2 easiest to get to bolts, one on each side, and put in about 4 - 5" long ones. Remove the other 4 and slide the trans back as far as the long bolts will let it go. Remove the flex plate bolts with a long box-end wrench.

Installation is the reverse of removal.

Worry about the motor some other time. Save up your pennies. You're not going to get any motor worth a crap for $1000 - 1500. That's FANTASY LAND. If that's all the money you've got, just fix the car, and keep saving.

 

That's a great idea, keeps the trans and engine aligned.. Remove the distributor cap when you let the engine/trans sag downward after removing the trans crossmember.. Otherwise you might break the cap/rotor..

I also wouldnt do a 350 swap unless I had a great deal on a Vortec headed engine from the 90's.. Or a steal of a deal on a used, built, 350/383.. With good heads, etc.

 

You don't.

That's the whole idea behind "support the transmission".

Which is not to say, don't remove the ignition parts; only, it's not necessary if the process is done carefully.

 

You probably shouldn't have mentioned the flexplate...

You have me confused on one point - you say you have the Edelbrock carb (along with other stuff) that you will be transferring over to the 350. But, then you say your carb "won't" be computer controlled - is it installed on the 305 now?

Reason I'm asking is because, in my personal opinion, the Edelbrock carb is a very bad idea. It is no better than the stock q-jet (worse, actually), and going to it drives other expenses that you cannot avoid. Keeping the stock q-jet will only cost a small amount for tuning (secondary rods and hangers), and you'll keep the knock sensor function (using the Edelbrock carb will defeat the knock sensor function). The stock computer q-jet is, again in my personal opinion, the best street/performance carb out there, factory or aftermarket. If you choose a cam that won't play well with the computer carb, it won't be very street-friendly, either.

If you use your 305 heads, you'll need to use pistons with about 10-12cc dish. Most truck engines came with pistons like that.

What cam to get depends upon whether you get a roller lifter 350 block, or settle for an older flat tappet block (or a new block that hasn't had the roller lifter provisions machined). Something in the 260-ish advertised duration will make for a good step up over the factory cam, while maintaining good street manners.

 

I've kinda taken all the advice given. I'm a drop the tranny completely n change the flexplate but i bought a engine stand and ima start building up a good 350 block to replace the 305. I don't have the factory q-jet so I guess I'm sol on that . Thanks for the advice about the pistons . I'll prolly get a older block without the roller. once I get to the scrap yard n see what's available I'll have the casting #s n ask for some specific options for the best way to build up that block. I'm not looking to build a monster just something around 300-350 hp. If anybody best way to accomplish that using most if not all the top end parts I already have let me kno. Thanks again for all the advice so far tho.

 

Most 350s available now were originally put in light trucks. If it is '87-later, there's a better than 50% chance it is roller-ready (all of the castings were of the roller lifter type, but not all of them were machined for them). Roller lifters really are superior, and it only gets more-so because the latest oils are formulated assuming roller lifters. It isn't hard to find the roller components (eBay, etc.) to convert a roller-ready block to roller lifters/cam.

If you limit the selection to '96-'99 light truck 350s, you'll be one more step up with heads that will flow better than your 305 heads worked over, without having to worry about compression being too high.

Regardless, I would plan on going completely through the 350. The latest non-Vortec engines are almost 20 years old, and I've known quite a few guys with '96-'99 trucks who had bearing fail on them (along with a couple of earlier 90's trucks).