My car is a 1975 4-spd coupe with P/S and factory air. Original 350 still in it. It is a fun car buts lacks muscle. I have been shopping for a big block to swap and found a rebuilt 396-402 block casting # 3969854 with 3993820 cast # heads for what seems to be a fair price at 3700. It is fresh rebuild and is lacking only the dist and pulleys. Would like advice about clutch, headers, exhaust and stuff that will enhance the swap. I read search info about removing the cast intake and using a Torker 2?
Thanks to forum members for answers.

 

if going big block, it is hard to justify that small. 454 or stay with the orig engine.

 

The 454's I come across all need rebuild with original buy in near the same price. Most are pulled from RV's. I see a place in Phoenix selling the 396 big block for 6495.00 with similar specs.

 

YOu need to get an AIM for a year that had a 427 or 454 and find the pulleys, alternator mount, correct pulley and power steering pulley/ mount and hunt those down. They can get really pricey so search our for sale section. These guys came through for me. Ebay is another good place fr stuff you cant find here. You are goiing to need a big block hood at minimum or a L88 hood...start shopping for those. Before you pull the 350 you have check the timing compared to Lars papers. 36 degrees all in before 3000 rpm will liven up even the lamest corvette motor. After that you arent going to notice anything with just and intake and header swap. You wwill need to get better heads, preferably a good aluminum head with a smaller combustion chamber to increase your compression and then the intake and headers will actually do something. The best intake for a street motor is generlally the RPM dual plane but it needs alot of hood space.

A motor is a pump and the more air you move through it efficiently, the more horsepower it makes. After you get all that you can start improving the internals, mainly the cam. Then if you are still power hungry you will need better pistons to increase the compression. If you want over 500 hp you will have to upgrade the rest of the internals.

And be careful of rebuilds from people that you wouldnt trust with your wallet, even some of those will screw you

 

I've been on the fence about the big block swap. I figured since the last 454 c3 was 1974 would not be much different than a 383 or 400 small block swap. I have looked at both of those options available from local folks for close to same price until pulleys and brackets come into the mix. My current 350 runs real nice, smooth and I do like the numbers matching thing but my v-6 Honda has more pep.

 

I have a v6 Honda as well..240hp in a ridgeline..

The 355 in my 74 with flat top pistons and 64 cc heads, sidepipes and midrise dual plane manifold is around 400hp and does in fact have much more power than my honda.. is your original engine a forged internal l82 or an l48? If its and l48 you can really wake it up with 55-64 cc heads. Also its a slippery slope.. you may want different gearing since that what gives your honda the perceived power you get when you take off.. our 74s mostly shipped with 3.08 gears. Im swapping 3.55s into my car with an overdrive transmission to give me better low end launch power as well as better fuel economy and a quieter ride on the highway.

 

if its a proper rebuild thats not a bad deal for the $. Ive had some quick 396 cars.
A decent intake, cam headers it should run pretty good. A real nice set of oval ports wakes them up

 

Rebuilt by who (as hinted above)? MANY rebuilt engines are very questionable.
I wouldn't ruin a all #'s car.
Rebuild you matching #'s engine.

 

and i feel the 820 head is a little big for a 396. 113 cc chambers. you will get 8.9:1 with the 24 cc pistons in a standard 396-325 with .041 head gasket. and what is involved in the rebuild? rings and bearings and it is "rebuilt" at a total cost of 100 to 200 bucks. orange paint included. or real rebuild. rebore, new pistons. .010 cut on the crank. and if so, what pistons? what crank? what rods? rebalanced?

 

1975 is L48...my 18 ridgeline is rated 280hp. 0-60-6.6. Thanks for the input. Taking a step back from the big block for now. May revisit this Fall but going to enjoy it for what it is for now.

 

heads, cam, exhaust.